1
Simple & Compound interest
Simple & Compound Interest
1.
In SI the Interest is calculated only on PRINCIPAL.
In CI the Interest is calculated on Amount (Principal + Interest).
SI for every year remains same. CI for every year increases.
SI & CI for the first year is same.
CI on the present is year is calculated on the Amount of the Previous Year.
2.
P = Tk.1000, R% = 10% p.a., T = 2 years, SI =?
3.
P = Tk.1000, R% = 10% p.a., T = 2 years 3 months, SI =?
4.
P = Tk.1000, R% = 10% p.a., T = 2 years 146 days, SI =?
5.
P = Tk.1000, for first 2 yrs, R% = 10% p.a., for next 1 yrs, R% = 20% p.a., for next 2
yrs, R% = 25% p.a., SI after 5 years =?
6.
Kona deposited Tk.505 into her savings account. If the interest rate of the account
is 5% per year, how much interest will she have made after 4 years?
[BB-AD – 2021 (FBS)]
(A) Tk.252.50 (B) Tk.606
(C) Tk.10,100 (D) Tk.101
7.
The interest changed on a loan is ‘P’ per Tk.1000 for the first quarter (3 months)
+
and ‘Q’ per Tk.1000 for each month after the first quarter. How much interest
=
10P
+
10×9Q
will be charged for the first year on Tk.10,000?
[BB-Officer – 2022 (BIBM)]
= 10(P+9Q)
(A) 10(P+Q)
8.
(B) 10(P+9Q) (C) 4P+9Q
(D) None of these
If the ratio of principal and yearly amount be in the ratio 25:28, then the yearly rate
of interest is –
[7 Banks & FI’s –SO – 2021 (AF)]
(A) 3%
(B) 12%
(C) 10 %
(D) 8%
6% nvi my‡` bq gv‡m 10,000 UvKvi Dci my` KZ UvKv ?
(K) 450 UvKv
9.
(L) 500 UvKv
(M) 600 UvKv
(25 BCS)
(N) 650 UvKv
How much interest will Tk.10,000 earn in 9 months at an annual rate of 6%?
[BB-AD – 2001]
(A) 900
(B) 750
(C) 600
(D) 450
kZKiv 5 UvKv nvi my‡` 20 eQ‡i my‡`-Avm‡j 50,000 UvKv n‡j, g~jab KZ ?
10.
10000×(6/100)×(9/12) =
450
(14 BCS)
(K) 20,000 UvKv (L) 25,000 UvKv (M) 30,000 UvKv (N) 35,000 UvKv
1
11.
Principal = 25
Amount = 28
So, interest = (28-25) = 3
Then Rate of interest
= (3/25)*100 = 12%
evwl©K 4 /2% mij my‡` KZ UvKv wewb‡qvM Ki‡j 4 eQ‡i Zv 826 UvKv n‡e ?
(K) 458 UvKv
(L) 650 UvKv
(M) 700 UvKv
(20 BCS)
(N) 725 UvKv
4.5×4 = 18
118% is 826
So, 100% is 100×826/118 =
700
RvIqv` mv‡ne 500 UvKv 3 eQ‡ii Rb¨ e¨vs‡K Rgv ivL‡jb| 8(1/3)% nv‡i wZwb KZ UvKv mij
[15 Zg †emiKvwi wk¶K wbeÜb - 2018]
12. gybvdv cv‡eb?
(K) 100 UvKv
(L) 125 UvKv
(M) 525 UvKv
(N) 625 UvKv
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2
Simple & Compound interest
13.
What amount of money invested would earn interest of Tk.200 over 4 years at 10%
simple interest rate?
[BB-AD – 2001]
(A) 400
14.
(C) 600
(D) None of these
Tk.75 is charged as a simple interest on a loan which is taken for 3 years at an interest
rate of 5% per annum. What was the amount of loan in taka?
(A) 225
15.
(B) 500
(B) 350
(C) 475
(D) 500
(E) 550
How long will it take for an amount Tk.450 to yield Tk.81 as interest at 4.5% per
annum of simple interest?
[BKB – (Cash) – 2017; BDBL–(SO) – 2017 (AF)]
(A) 4 yrs
(B) 4.5 yrs
(C) 5 yrs
(D) 5.5 yrs
16.
In how many years taka 1800 will become taka 2250 if the simple interest rate is 5%
p.a.?
(A) 3
(B) 4
(C) 5
(D) 6
(E) None of these
17.
If the interest of Tk.H at H% in 4 years is Tk.H, then H =?
[BDBL–(SO) – 2017 (AF); Sonali Bank-Off./JO - 2010]
(A) 25
(B) 20
(C) 30
(D) 32
450 UvKv evwl©K 6% my‡` KZ eQ‡i my‡`-Avm‡j 558 UvKv n‡e ?
18.
(K) 3 eQ‡i
(L) 4 eQ‡i
(M) 5 eQ‡i
(40 BCS)
(N) 6 eQ‡i
558 – 450 = 108
6% of 450 = 27
108/27 = 4 (B)
19.
What is the total interest on Tk. 800 at 12.5% per annum for 9 months?
1/8 of 800 = 100
[MTB-MTO – 2018] ¾ of 100 = 75
(A) Tk.22
(B) Tk.75
(C) Tk.88
(D) Tk.110
20.
What annual rate of interest was paid if Tk.50000 earned Tk.3000 in interest in 2
years?
[BB-AD – 2001]
(A) 3%
(B) 6%
(C) 9%
(D) 12%
21.
What annual rate of interest was paid if Tk.60000 earned Tk.6000 in interest in 5
years?
[BB-AD – 2008]
(A) 2%
22.
[Ans. A]
(B) 3%
(C) 4%
(D) 5%
(E) 6%
What is the annual interest rate on an account that earns Tk.948 in simple interest
over 36 months with an initial deposit of Tk.7900?
[BB-AD – 2021 (FBS)]
(A) 5%
(B) 4%
(C) 3%
(D) 3.3%
hw` 1000 UvKvi Dci 6 gv‡m jvf nq 65 UvKv, Z‡e jv†fvi kZKiv nvi KZ?
[PKB-EO – 2017]
23.
(K) 8%
24.
(M) 13%
(N) 15%
A moneylender charged Tk.25 as simple interest on a loan of Tk. 150 for 1/6 years.
What was the rate of interest per annum?
(A) 125
25.
(L) 12%
(B) 100
(C) 75
(D) 50
(E) 25
The difference between interest received by A and B is Tk.405 on Tk.4500 for 3 years.
What is the difference in rate of interest?
(A) 1.5%
(B) 2%
(C) 2.7%
(D) 3%
(405/3)*(100/4500) = 3%
(E) None of these
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3
Simple & Compound interest
26.
The simple interest on a sum of money will be Tk.600 after 10 years. If the principal is
trebled after 5 years, what will be the total interest at the end of the tenth year?
[BB-AD – 2014; PKB-2014, written]
(A) Tk.600
(B) Tk.900
(C) Tk.1200
(D) Tk.1500
27.
Simple interest rate of a bank was reduced to 5% from 7%. As a consequence,
Karim’s income from bank interest was reduced by Tk.2100 in 5 years? How much
was Mr. Karim’s initial deposit with the bank?
(Pubali Bank-2016, written)
28.
If rate of interest changes from 2% to 2.5%, then 2 years simple interest increases by
Tk.120. Find the principal.
29.
Hasib took a loan of Tk.1400 with simple interest for as many years as the rate of
interest. If he paid Tk.126 as interest at the end of the loan period, what was the rate
of interest?
[Mercantile Bank – 2015]
(A) 3%
30.
(C) 9%
(D) 12%
(E) None of these
If the ratio of simple interest and principal is 8 ∶ 25/2 and rate of interest is equal P : I = 25/2 : 8 = 25 : 16
Now, P × (R/100) × T = I
to the time invested, then find the time of investment?
=> 25 × (T/100) × T = 16
[Janata & Rupali Bank-Officer – 2019]
(A) 8 years
31.
(B) 6%
(B) 10 years
(C) 12 years
=> T² = 64
So, T = √ = 8 yr [Ans.]
(D) 16 years
A sum was put at simple interest at a certain rate for 3 years. Had it been put at 2%
higher rate, it would have fetched Tk.360 more. Find the sum.
(A) Tk.4000
(B) Tk.5000
(C) Tk.6000
2%*3 i.e. 6% is Tk.360
So, 100% is Tk.6000
(D) Tk.9000
32.
The interest on a certain deposit at 4.5% p.a. is Tk.202.50 in one year. How much will
4.5% ≡ Tk.202.50
the additional interest in one year be on the same deposit at 5% p.a.?
0.5% ≡ 0.5×202.5/4.5 =
[BB-Officer-Cash – 2016] 22.50
(A) Tk.20.25
(B) Tk.22.50
(C) Tk.25
(D) Tk.42.75
33.
Tk.800 becomes Tk.956 in 3 years at a certain rate of simple interest. If the rate of
interest is increased by 4%, what amount will Tk.800 become in 3 years?
956 + 800×4%×3
[BB-AD – 2016] = 956 + 96 = 1052
(A) 1020.80
(B) 1025
(C) 1052
(D) None
34.
A sum of Tk.600 amounts to Tk.720 in 4 years at simple interest. What will it amount
to if the rate of interest is increased by 2%?
(Janata Bank-EO - 2017)
(A) Tk.750
(B) Tk.768
(C) Tk.800
(D) None
my‡`i nvi 5% e…w× cvIqvq 375 UvKvi mij my` 75 UvKv e…w× cvq| Zvn‡j mgq KZ ?
35.
(K) 2 eQi
36.
(L) 4 eQi
(M) 6 eQi
720 + 600×2%×4
= 720+48 = 768
(N) 8 eQi
5% of 375 = 18.75
75/18.75 = 4 yr
A person borrows Tk.5000 for 2 years at 4% p.a. simple interest. He immediately
1
lends it to another person at 6 % p.a. for 2 years. Find his gain in the transaction
4
per year.
[PBL: JO-2016]
(A) Tk.1125.50 (B) Tk.125
(C) Tk.150
(D) Tk.167.50
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4
Simple & Compound interest
12.5% interest means, for
37.
If an amount kept for a year gives 12.5% interest, then in how many years the principal Tk.100, interest is
Tk.12.5
cumulative interest generated will be equal to the principal amount?
[IBA-MBA: 63 intake, Jan-2021] So, cumulative interest to
(A) 3
38.
(B) 5
(C) 6
(D) 7
(E) None of these
be equal to principle 100,
Required time =
= 8 yr
‡Kvb Avmj UvKvi 5 eQ‡ii my`, Avm‡ji 5/8 Ask n‡j, evwl©K kZKiv my‡`i nvi KZ?
kZKiv evwl©K KZ nvi my‡` 5 eQ‡ii my`, my`-Avm‡ji 1/5 Ask n‡e ?
[gva¨: mn: wk¶K - 2000]
39.
(K) 5%
(L) 10%
(M) 15%
(N) 20%
‡Kvb Avmj 3 eQ‡i gybvdv-Avm‡j 5500 UvKv nq| gybvdv Avm‡ji 3/8 Ask n‡j gybvdvi nvi KZ?
[Combined-SO – 2018; 38 BCS; Class-8 (2.1)]
40.
(K) 10%
(L) 12.5%
(M) 15%
(N) 12%
Profit for 3 yr = 3
So, profit for 1 yr = 1
Then, Profit % = (1/8) =
12.5%
‡Kvb Avmj 5 eQ‡i my‡`-Avm‡j 550 UvKv Ges my` Avm‡ji 3/8 Ask| Avmj Ges kZKiv evwl©K
[Class–8]
41. my‡`i nvi KZ?
(K) 400, 7.5% (L) 400, 7.3% (M) 450, 7.5% (N) 400, 6.5%
‡Kvb g~jab 3 eQ‡i mij my‡`- g~‡j 11000 UvKv nq| my` Avm‡ji wZb-Aógvsk n‡j, Avmj I
[21 BCS, written]
42. my‡`i nvi wbY©q Kiæb (K) 5000, 7.5%
43.
(L) 422, 7.5%
(M) 4000, 6.5%
(N) 8000, 12.5%
evwl©K 5% nvi my‡` KZ eQ‡i my` Avm‡ji 5/16 Ask n‡e?
‡Kv‡bv wbw`©ó mg‡q gybvdv-Avmj 5600 UvKv Ges gybvdv Avm‡ji 2/5 Ask| gybvdv evwl©K kZKiv
8 UvKv n‡j, mgq wbY©q Ki -
44.
= 40/100
‡Kv‡bv wbw`©ó mg‡q gybvdv-Avmj 5600 UvKv Ges gybvdv Avm‡ji 40 kZvsk| gybvdvi evwl©K nvi 2/5
T = 40/8 = 5 yr
8% n‡j, mgq wbY©q Kiæb [cªwZi¶v gš¿Yvjq - 2018]
(K) 7 eQi
45.
(L) 6 eQi
(M) 5 eQi
(N) 4 eQi
P = 100%
Interest = 200%
Time = 200/14 = 14(2/7) yr
kZKiv evwl©K 14 UvKv nvi my‡` KZ eQ‡i my`, Avm‡ji wظb n‡e ?
mij my‡`i nvi kZKiv KZ UvKv n‡j †h ‡Kv‡bv g~jab 8 eQ‡i my‡`-Avm‡j wZb¸Y n‡e ?
46.
(10 BCS)
(K) 12.5 UvKv
47.
48.
49.
(L) 15 UvKv
(M) 20 UvKv
(N) 25 UvKv
GKB nvi gybvdvq †Kvb Avmj 6 eQ‡i my‡`g~‡j wظY n‡j KZ eQ‡i Zv my‡`g~‡j wZb¸Y n‡e?
A sum becomes 5 times in 20 years at simple interest, Find R%?
mij my‡`i nvi kZKiv KZ UvKv n‡j †h ‡Kv‡bv g~jab 20 eQ‡i my‡`-Avm‡j 5 ¸Y n‡e ?
A=3
So, Pr. + Int. = 1+2
R% = (2/8)×100 = 25%
P = 100%
I₁ = 100%
I₂ = 200%
Time = 200*6/100 = 12 yr
A = 5; So, Pr. + Int. = 1+4
R% = (4/20)×100 = 20%
A sum becomes 4 times in 15 years at SI. At the same rate of interest, how many years
it becomes 20 times?
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5
Simple & Compound interest
50.
If a sum of taka invested amounts to BDT 460 in 3 years and amounts to BDT 500
in 5 years, then what is that invested sum in BDT?
[Bangladesh Bridge Authority-AD – 2020 (IBA)]
(A) 300
51.
(C) 18%
(D) 20%
(E) 26%
(B) 180
(C) 200
(D) 300
(E) None
(B) 175
(C) 200
(D) 210
Int. for 1 yr = (300-240)/3 =
20
Int. for 2 yr = 20*2 = 40
Principal = (240-40) = 200
(E) 250
(B) 4%
(C) 5%
(D) 6%
A sum of money amounts to Tk.9800 after 5 years and Tk.12005 after 8 years at the
same rate of simple interest. The rate of interest per annum is:
[PKB-SO – 2021; Rupali Bank – 2013]
(A) 5%
56.
(B) 15%
Int. for 1 yr = (500-460)/2 =
20
Int. for 3 yr = 20*3 = 60
Principal = (460-60) = 400
R% = (20/400)*100 = 5%
A sum of money at simple interest amounts to Tk.5600 in 2 years and Tk.6500 in 5
years at the rate of –
[8 Bank – SO – 2021 (AF)]
(A) 3%
55.
(E) None
Annie invested a certain sum of money in a bank that paid simple interest. The
amount grew to Tk.240 at the end of 2 years. She waited for another 3 years and got a
final amount of Tk.300. What was the principal amount that she invested at the
beginning?
[NCC Bank-PO – 2022; UCBL-PO – 2017]
(A) 150
54.
(D) 450
If a sum of money invested amounts to Tk.300 after 3 years and Tk.500 after
another 5 years, then what is the money invested?
(A) 120
53.
(C) 400
The sum of principal and simple interest of a certain amount of money would be
Tk.460 after 3 years from now and Tk.500 after 5 years from now. What is the related
interest rate?
[Primary Asstt. Teacher – 2015; BB-AD – 2010]
(A) 5%
52.
(B) 350
(B) 8%
(C) 12%
(D) 15%
A certain sum of money amount to Tk.1008 in 2 years and to Tk.1164 in 3.5 years.
Find the sum and the rate of interest.
[Pubali Bank: SO, written]
Int. for 1 yr = (12005-9800)/(85) = 2205/3 = 735
Int. for 5 yr = 735*5 = 3675
Principal = (9800-3675) =
6125
R% = (735/6125)*100 = 12%
1-yr interest = (11641008)/(3.5-2) = 156/1.5 = 104
Principal = (1008 - 104×2) =
800
Rate of interest =
(104/800)×100 = 13%
‡mwjg 6% mij my‡` e¨vs‡K 10,000 UvKv wewb‡qvM K‡i| Avi KZ UvKv 8% mij my‡` wewb‡qvM
Ki‡j ‡m ‡gv‡Ui Dci 7% nv‡i my` cv‡e?
[NSI-AD – 2019 (IBA)]
57.
(A)
58.
59.
18500
(B) 18750
(C)
19000
(D)
19350
(E)
‡KvbwUB bq
A total of Tk.1200 is deposited in two savings accounts for one year, part at 5% and
the remainder at 7%. If Tk.72 was earned in interest, how much was deposited at
5%?
[BB-AD – 2012]
(A) 300
(B) 500
(C) 600
(D) 700
Mr. Zaman had Tk.2000 to invest. He invested part of it at 5% per year, and the
remainder at 4% per year. After one year, his investment grew to Tk.2095. How much
of the original investment was at the 5% rate?
(A) Tk.500
(B) Tk.750
(C) Tk.1000
(D) Tk.1250
(E) Tk.1500
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6
Simple & Compound interest
60.
A sum of taka 1550 is lent out in two parts; one at 8% and another at 6%. If the total
annual income is taka 106, find the money lent at each rate.
[Janata Bank – 2015]
A man invests a part of Tk.10,000 at 5% and the remainder at 6%. The 5%
investment yields annually Tk.76.50 more than the 6% investment. The amount
invested at 6% is –
⇒ 50000 – 5x – 6x = 7650
⇒ 11x = 50000 – 7650 = 42350
Alternate:
Ratio of Rate ⇒ 5 : 6
For getting equal interest,
ratio of Investment ⇒ 6 : 5
Tk.76.50 more yields from
amount invested at 5%
Now, 10000 - 76.5/0.05 =
10000 – 1530 = 8470
So, amount invested at 6%
⇒x=
= 8470 ×
(A) Tk.3600
61.
(B) Tk.3550
(C) Tk.3850
(D) Tk.4000
Let, he invested x taka at 6% and (10000-x) taka at 5% profit.
So, 5% of (10000-x) – 6% of x = 76.50
–
⇒
= 76.50
= 3850
So, he invested Tk.3850 at 6%. [Ans.]
62.
63.
Someone plans to invest Tk.x in the bond of 'M' Company, which pays 10%
interest and Tk.y in 'N' Company bonds, which pay 9% interest. He will invest
Tk.9000 and require that he receives Tk.850 as interest. How much should he
invest in each company?
[Sonali Bank-SO – 2018]
GKRb e¨w³ 20,000 UvKv †_‡K wKQy UvKv evwl©K 10% gybvdvq Ges evwK UvKv evwl©K 12%
3
gybvdvq wewb‡qvM Ki‡jb| GK eQi ci wZwb me©‡gvU wewb‡qv‡Mi 10( /4) gybvdv †c‡jb|
wZwb gybvdvi cªwZ nv‡ii Rb¨ KZ UvKv wewb‡qvM K‡iwQ‡jb?
[41 BCS, written]
64.
Total profit got =
of 20000 =
× 20000 = Tk.2150
Let, he invested x taka at 10% and (20000-x) taka at 12% profit.
So,
+
= 2150
⇒ 10x + 240000 – 12x =
215000
⇒ 2x = 25000
⇒ x = 12500
So, he invested Tk.12500 at
10% profit
And (20000-12500) i.e.
Tk.7500 at 12% profit
10%
3×10% + 2×8% = 300+160 =
460. Avg. = (460/5000)×100 =
9.2%
(3×10+2×8)/(3+2) = 46/5 =
9.2%
A, B-‡K 3 eQ‡ii Rb¨ 400 UvKv Ges C-‡K GKB nv‡i 4 eQ‡ii Rb¨ 500 UvKv avi w`j| hw` ‡m
400*(R/100)*3 +
500*(R/100)*4 = 160
32R = 160
R = 160/32 = 5%
gybvdvq 3000 UvKv Ges 8% gybvdvq 2000 UvKv wewb‡qvM Ki‡j †gvU gyja‡bi Dci M‡o
kZKiv
KZ nv‡i gybvdv cvIqv hv‡e?
(37 BCS)
65.
(K) 9%
(L) 9.2%
(M) 8%
(N) 8.2%
‡gvU 160 UvKv my` cvq, Z‡e my‡`i nvi KZ ?
(K) 8%
(L) 6%
(M) 5%
(N) 4%
[160/(3*400 + 4*500)] =
160/3200 = 1/20 = 5%
500 UvKvi 4 eQ‡ii my` Ges 600 UvKvi 5 eQ‡ii my` GK‡Î 500 UvKv n‡j my‡`i nvi KZ?
(16 BCS)
67.
= 8470 ×
= Tk.3850
GKRb wewb‡qvMKvix 80,000 UvKvi wKQy c«wZ 6 gvm AšÍi 5% nvi my‡` Ges Aewkó
evrmwiK 12% nv‡i GKwU ‡mwfsm e¨vs‡K Rgv Kij| eQi ‡k‡l wZwb 9000 UvKv my`
‡c‡jb| Zvn‡j wZwb 12% nvi my‡` KZ UvKv wewb‡qvM K‡ib?
[35 BCS, written]
66.
5% of (10000-x) - 6% of x
= 76.50
x = 3850
(K) 5%
(L) 6%
(M) 10%
(N) 12%
500*(R/100)*4 +
600*(R/100)*5 = 500
50R = 500
R = 500/50 = 10%
[500/(500*4 + 600*5] =
500/5000 = 1/10 = 10%
Upgrade yourself; it saves a lot of extra effort
7
Simple & Compound interest
GK e¨w³ Zvi g~ja‡bi
68.
(C) 9 : 18
(B) 4.8%
(C) 5.0%
(B) Tk.6240
(C) Tk.6500
(D) 5.2%
(D) Tk.9600
A man purchased a cow for Tk.3000 and sold it the same day for Tk.3600,
allowing the buyer a credit of 2 years. If the rate of interest be 10% per annum,
then the man has a gain of:
[5 Banks Officer (Cash) – 2021]
(B) 5%
(C) 7.5%
(D) 10%
A trader buys a chair for Tk.600 and sells it for Tk.765 at a credit of 4 months.
Reckoning money worth of 6% p.a., his gain percent is –
(A) 20%
(B) 22.5%
(C) 25%
[Ans. A]
(D) 2 : 4
In order to obtain an income of Tk.650 from 10% stock at Tk.96, one must make
an investment of:
[5 Banks Officer (Cash) – 2021]
(A) 0%
73.
(B) 6 : 8
C) 6600
(N) 7200 UvKv
(PKB–Programmer – 2019-AUST)
(A) Tk.3100
72.
(M) 6600 UvKv
A person invested part of Tk.45000 at 4% and the rest at 6%. If his annual incomes
from both are equal, then what is the average cost of interest?
(A) 4.6%
71.
(L) 6000 UvKv
Bank X pays a simple interest of Tk.80 on a principal of Tk.1000 annually. Bank Y
pays a simple interest of Tk.140 on a principal of Tk.1000 annually. What is the ratio
of the interest rates of Bank X and bank Y?
[BB-AD – 2012]
(A) 4 : 7
70.
Ask Ges Aewkóvsk h_vµ‡g 7%, 8% Ges 10% evwl©K mij
my‡` wewb‡qvM K‡i| hw` Zvui evwl©K Avq 561 UvKv nq, Z‡e Zvi ‡gvU wewb‡qvM KZ?
(K) 5400 UvKv
69.
Ask,
(D) 27.5%
R% => 4 : 6
Since SI is same, so Principal is
indirectly proportional to R%
Then, Principal => 6 : 4
So, Avg R% = (4×6 + 6×4)/(6+4)
= 48/10 = 4.8%
Assume Book value as Tk.100 (as
it is not given in the question)
Now, 10% of Tk.100 = Tk.10
[stock is given on book value]
So, to obtain Tk.10, investment =
Tk.96
Then, to obtain Tk.650, investment
= (96×650)/10 = Tk.6240
CP = Tk.3000
FV of Tk.3000 after 2 yrs at
10% simple interest = 3000 +
3000 × (10/100) × 2 = 3600
Again, net payable after 2
years = Tk.3600
So, gain = (3600-3600) = 0
Gain % = 0%
CP = Tk.600
FV of Tk.600 after 4 months @
6% p.a. = 600×(6/100)×(4/12) =
612
So, Profit = (765-612) = Tk.153
Profit % = (153/612)×100 = 25%
2600 UvKv Avmj Giƒc `yB fv‡M avi ‡`qv n‡jv hv‡Z kZKiv 10 UvKv nv‡i 5 eQ‡ii 1g fv‡Mi my`
Investment Ratio, 1st : 2nd
n‡e Ab¨ fv‡Mi kZKiv 9 UvKv nv‡i 6 eQ‡ii my‡`i mgvb| kZKiv 10 UvKv nv‡i KZ UvKv avi = (9×6) : (10×5) = 27 : 25
= (27 : 25) × 50
74. ‡`Iqv n‡qwQj?
(K) 1150
75.
76.
(M) 1350
(N) 1550
A, B and C invested different amounts of money at different simple rate of interest for
different time periods. A @ 10% for 2 years; B @ 20% for 1½ years and C @ 15% for
1 year. At the end of time periods, interest received by 3 persons is same. Find the
ratio of their investment?
A sum of Tk.1440 is lent out in three parts in such a way that the interests on first
part at 2% for 3 years, second part at 3% for 4 years and third part at 4% for 5 years
are equal. Then the difference between the largest and the smallest sum is –
(A) Tk.200
77.
(L) 1250
= 1350 : 1250 [Sum =
2600]
(B) Tk.400
(C) Tk.460
(D) Tk.560
Divide Tk.2379 into 3 parts so that their amounts after 2, 3 and 4 years respectively
may be equal, the rate of interest being 5% per annum at simple interest. The first
part is:
110A = 115B = 120C
=> 22A = 23B = 24C
A : B : C = (23*24) : (22*24) :
(22*23) = 276 : 264 : 253
So, A = 2379*(276/793) = 828
Upgrade yourself; it saves a lot of extra effort
8
Simple & Compound interest
GK e¨w³ Zvi 14, 12 I 10 eQ‡ii 3 cy·K 25,300 UvKv Ggb fv‡e fvM K‡i w`‡jb ‡h Zvi wZb
cy‡Îi c«‡Z¨K ‡K 18 eQi eq‡m mvevjK n‡j 5% mij my‡`i nv‡i GKB UvKv cv‡e| H e¨w³ ga¨g
78.
cy·K KZ UvKv w`‡q‡Qb?
(K) 9100
(L) 8400
(M) 7800
(N) 6500
79.
A person earns yearly interest of Tk.920 by investing Tk.X at 4% and Tk.Y at 5%
simple interest rate. If he had invested Tk.X at 5% and Tk.Y at 4% simple interest
rate, then his yearly interest earning would have been reduced by Tk.40. Find out the
amount of X and Y.
80.
Luna deposited a certain amount of money for a fixed period of time. On maturity,
she received a total of Tk.45000 when the ratio of interest and investment became 2:5.
If the interest rate was 3.6%, calculate the time period for which the money was
invested?
81.
Rahim borrowed Tk.800 at 6% per annum and Karim borrowed Tk.600 at 10% per
annum. After how much time will they both have equal debts?
(A) 50/3 yr
82.
(B) 83/3 yr
(C) 44/3 yr
(B) Tk.16000
60t – 48t = 200
=> t = 200/12 = 50/3 yr
(D) 20/3 yr
A man is in need of money for 120 days. He asked the banker and the banker charged
Tk.360 at 6%. What was the amount asked for?
(A) Tk.15000
120A = 130B = 140C
=> 12A = 13B = 14C
A : B : C = (13*14) : (12*14) :
(12*13) = 182 : 168 : 156
So, B = 25300*(168/506) =
8400 [Ans.]
(C) Tk.18000
(D) None
1
Effective R% for 120 days
= 6*120/360 = 2%
Now, 2% ≡ Tk.360
So, 100% ≡ Tk.18000
1
iKxe mv‡ne 3,73,899 UvKv e¨vs‡K Rgv ivL‡jb| 7 /2 eQi ci wZwb Avmj UvKvi 1 /4 Ask my` In 7.5 yr = 5/4
So, in 1 yr = (5/4)/(15/2) =
(33 BCS)
83. †c‡jb| e¨vs‡Ki my‡`i nvi KZ ?
1/6
1
(K) 12 /2%
2
(L) 16 /3%
1
(M) 8 /3%
1
(N) 11 /9%
And, 1/6 = 16(2/3)%
84.
evwl©K kZKiv 6 UvKv gybvdvq 500 UvKvi 4 eQ‡ii gybvdv hZ nq, evwl©K kZKiv 5UvKv gybvdvq
KZ UvKvi 2 eQi 6 gv‡mi gybvdv ZZ n‡e ?
[Class-8 – 2.1]
I => 500×4×(6/100) = 120
R% => 5×2.5 = 12.5%
P => 120×100/12.5 = 960
85.
‡Kvb Avmj 8% nvi my‡` 3 eQ‡i my‡`-Avm‡j 1860 UvKv nq| KZ eQ‡i Zv my‡`-Avm‡j
2040 UvKv n‡e?
1860 tk. - - - 124%
2040 tk. - - - 136%
Interest = (136-100) = 36%
Time = 36/8 = 4.5 yrs
kZKiv evwl©K ‡h nv‡i ‡Kv‡bv g~jab 6 eQ‡i my‡`g~‡j (gybvdv- g~ja‡b) wظb nq, ‡mB nv‡i KZ UvKv
4 eQ‡i m‡y`g~‡j 2050 UvKv n‡e ?
[NSI-AD – 2017]
86.
Rate of interest = (2-1)/6 = 1/6
So, 4 yrs interest = 4×(1/6) =
4/6. Now, (4+6) i.e. 10 unit
≡Tk.2050
Then, 6 unit ≡ 6×2050/10 =
Tk.1230 [Ans.]
(K) 1225 UvKv (L) 1230 UvKv (M) 1240 UvKv (N) 1245 UvKv
87.
6500 UvKv ‡h nvi gybvdvq 4 eQ‡i gybvdv-Avm‡j 8840 UvKv nq, H GKB nvi gybvdvq KZ UvKv 4 6500 : 8840 = P : 10200
P = 6500×10200/8840 =
eQ‡i gybvdv-Avm‡j 10200 UvKv n‡e?
7500
8% mij gybvdvq 6,000 UvKv wewbh‡qv‡M 5 eQ‡i ‡h gybvdv nq, ‡Kvb mij nv‡i 10,000 UvKv
6×5×8 = 10×3×R
88. wewbh‡qv‡M 3 eQ‡i H gybvdv n‡e?
=> R = 8
(K) 12%
(L) 10%
(M) 9%
(N) 8%
89.
If a principal P becomes Q in 2 years when interest R% is compounded half-yearly
and if the same principal P becomes Q in 2 years when interest S% is compounded
annually, then which of the following is true?
[7 Banks & FI’s –SO – 2021 (AF)]
(A) R > S
(B) R = S
(C) R < S
(D) None
Since interest is compounded
half yearly at R% p.a. the value
of R will be lesser than the
value of S.
Upgrade yourself; it saves a lot of extra effort
9
Simple & Compound interest
90.
Principal = Tk.1000, Rate of interest = 20% p.a. compounded yearly, Time = 3 years.
Amount =?
91.
Principal = Tk.1000, Rate of interest = 20% p.a. compounded yearly, Time = 2½
years. Amount =?
evwl©K 10% gybvdvq 800 UvKvi 2 eQ‡ii Pµe…w× g~jab KZ ?
92.
93.
(K) 940 UvKv
(L) 960 UvKv
(M) 968 UvKv
[41 BCS]
800 ×
(N) 980 UvKv
×
= 968
A man deposits Tk.600 in a Bank at 10% interest rate compounded annually. At the
end of the second year, what will be the total amount including interest?
[BB-Officer (Cash) – 2001]
(A) 626
(B) 660
(C) 670
(D) 720
(E) 726
What would be the compound interest on Tk.77000 at 15
94.
1000×(6/5)×(6/5)×(6/5) =
1728
% per annum for 2
[One Bank-SCO – 2022]
years compounded annually?
(A) Tk.2725.75 (B) Tk.2527.57 (C) Tk.2227.57 (D) Tk.2520.57
95.
What would be the compound interest accrued on an amount of Tk.8000 at the rate of
15% p.a. in 3 years?
(A) Tk.4051
96.
(B) Tk.4167
⇒ 2500 × (
(C) Tk.10483.30
(D) Tk.10123.20
)
)
⇒ 2500 ×
⇒ 2852.91
[Ans.]
Alternate Solution:
4.5% of 2500 = 112.5
4.5% of 112.5 = 5.06
4.5% of 5.06 = 0.23
Total interest = 112.5×3 +
5.06×3 + 0.23 = 352.91
So, Total amount to be paid
= 2500+352.91 = 2852.91
How much interest will Tk.1000 earn in one year at an annual rate of 8%, if interest is
compounded every 6 months?
[BB-Officer – 2001]
(A) 82.4
99.
(B) Tk.9720
Lamia owns a hairdressing salon. She borrows Tk.2500 from a bank to make
improvements to her beauty salon. She is charged 4.5% per year compound
interest. She pays the money back after 3 years. Calculate the total amount Lamia
must pay to the bank.
[Uttara Bank-PO – 2021 (FBS); Dhaka Bank-MTO –2018]
A = 2500 × (
98.
(D) Tk.4325
What will be the compound interest on a sum of Tk.25,000 after 3 years at the rate of
12% p.a.?
[Janata Bank: AEO-2015]
(A) Tk.9000.30
97.
(C) Tk.4283
15% = 10%+5%
15% of 8000 = 800+400 = 1200
15% of 1200 = 120+60 = 180
15% of 180 = 18+9 = 27
So, CI for 3 yrs = 1200*3 + 180*3
+ 27 = 4167
(B) 82
(C) 81.6
(D) 80
How much interest will Tk.1000 earn in one year at the annual interest rate of 20%, if
the interest rate is compounded every 6 months?
[BB-AD – 2010]
(A) 110
(B) 200
(C) 205
(D) 208
(E) 210
How much interest will Tk.2000 earn at annual rate of 10% in one year, if the interest
is compounded every 6 months?
[BB-AD – 2001; DBBL-MTO – 2001]
100. (A) 200
(B) 210
(C) 220
(D) None of these
(A) 200
(B) 205
(C) 210
(D) 220
[Ans. D; 205]
Upgrade yourself; it saves a lot of extra effort
10
Simple & Compound interest
Laboni bought a 1-year, Tk.10,000 certificate of deposit that paid interest at an
annual rate of 8 percent compounded semiannually. What was the total amount of
101. interest paid on her certificate at maturity?
[One Bank-SCO – 2022; Midland Bank: MTO – 2015]
(A) Tk.1,464
(B) Tk.864
(C) Tk.816
(D) Tk.800
(E) Tk.480
If the rate of interest is 10% per annum and is compounded half yearly, the
principle of Tk.4000 in 3/2 years will amount to –
[8 Bank – SO – 2021 (AF)]
102.
(A) Tk.4630.00 (B) Tk.4630.50 (C) Tk.4631.50 (D) Tk.4632.00
Find the compound interest on Tk.15,625 for 9 months at 16% per annum
compounded quarterly?
[Janata Bank – 2015]
103.
(A) Tk.1,851
(B) Tk.1,941
(C) Tk.1,955
(D) Tk.1,961
(E) None of these
Yearly R% = 20%
†hŠwMK gybvdvq g~jab 10,000 UvKv 2 eQ‡ii Rb¨ wewb‡qvM Kiv n‡jv| hw` †hŠwMK gybvdv So, half-yearly R% = 20/2
[43 BCS] = 10%
104. Aa© eQi wn‡m‡e aiv nq, Zvn‡j Pµe„w× g~jab KZ?
Now, 10% increase = 11/10
20%
(K) 12⁴
(L) 11⁴
(M) 10⁴
So, 10000×(11/10)×(11/10)
×(11/10)×(11/10) = 114
(N) 9⁴
If compound interest received on a certain amount in the 2nd year at 10% rate of
interest is Tk.1200, what will be the compound interest (in Tk.) for the 4 th year on 1200×(11/10) ×(11/10) =
105. the same amount at the same rate of interest?
1452
(A) Tk.1320
(B) Tk.1420
(C) Tk.1452
(D) Tk.1552
If the rate of interest is 20% per annum, compounded yearly and the interest on a
certain sum in the second year is Tk.250, then what will be the interest on the
250*(6/5)*(6/5)*(6/5) = 432
106. same sum in the fifth year?
(A) Tk.360
(B) Tk.400
(C) Tk.432
(D) Tk.518
A bank offers 5% interest compounded half-yearly. A customer deposits Tk.1600
each on 1st January and 1st July of a year. At the end of the year the amount he
107. would have gained by the way of interest is –
[Sonali Bank-Officer – 2018]
(A) Tk.121
(B) Tk.122
(C) Tk.123
(D) Tk.124
If Tk.1,000 is invested in an account paying 10% compounded monthly, how much
[BB-AD – 2006]
108. would be the nearest ending balance at the end of 10 years?
(A) Tk.1,104
(B) Tk.2,594
(C) Tk.2,840
(D) Tk.2,208
5%/2 = 2.5% =1/40
1600*1/40 = 40
1640*1/40 = 41
So, total interest = 40+40+41 =
121
1000(1 + 10/1200)^120 =
2707.04 [Ans. E]
(E) Tk.2,708
The compound interest at 10% per annum on a certain amount of money for two
109. years is Tk.10.50. Then what is the principal amount in Taka?
(A) 40
(B) 50
(C) 75
(D) 100
(E) None
An amount of money is invested in a savings account for two years. It increases by
Tk.52.50 in two years, after annual compounding at the rate of 10% per year.
[BB-AD – 2022 (BIBM)]
110. What is the amount invested initially?
(A) Tk.400
(B) Tk.300
(C) Tk.250
(D) Tk.200
Upgrade yourself; it saves a lot of extra effort
11
Simple & Compound interest
What is the difference between the compound interests on Tk.5000 for 1½ years at 4%
111. per annum compounded yearly and half-yearly?
(A) Tk.2.04
112.
(B) Tk.4.80
(C) Tk.3.06
(D) Tk.8.30
6.04 - 4 = 2.04
(E) None of these
Simple interest on a certain sum at 7% p.a. for 4 years is Tk.3584. what will be the
compound interest on same principal at 5% p.a. in 2 years?
The compound interest on a certain sum for 2 years at 10% per annum is Tk.525. The
simple interest on the same sum for double the time at half the rate of interest per
113. annum is:
[PKB-Officer, Cash – 2014]
(A) Tk.400
(B) Tk.500
(C) Tk.600
(D) Tk.800
There is 60% increase in an amount in 6 years at simple interest. What will be the
compound interest of Tk.12,000 after 3 years at the same rate?
[5 Banks Officer (Cash) – 2021 (AUST)]
114. (A) Tk.2160
(B) Tk.3120
(C) Tk.3972
(D) Tk.6240
(E) None of these
A certain amount increases by 60% in six years at a simple interest rate. What
will be the interest of Tk.12,000 after 3 years at the same rate compounded
annually?
[9 Banks & FI’s – Officer – 2022 (2018) – FBS, written]
Annual Rate of interest = 60/6
= 10%
Now, 10% of 12000 = 1200
Again, 10% of 1200 = 120
And, 10% o 120 = 12
So, total interest after 3 years =
1200×3 + 120×3 + 12×1 =
Tk.3972 [Ans.]
--R% = 60/6 = 10%
Effective R% in CI = 33.1%.
So, 33.1% of 12000 =
3600+360+12 = 3972
Find the compound interest at the rate of 10% per annum for four years on the
principal which in four years at the rate of 4% per annum gives Tk.1600 as simple
115. interest.
[Sonali Bank-Officer (FF) – 2019] 4641
(A) Tk. 4641
(B) Tk. 4732
(C) Tk. 4321
(D) Tk. 4899
The simple interest received on a sum of money at the end of 10 years is two times the
principle. At the same rate of interest, what would be the ratio of principal and
116. compound interest received at the end of two years?
[Combined Bank-Officer – Sonali, Janata, BKB, BDBL – 2019]
(A) 25 : 11
(B) 20 : 11
(C) 20 : 9
(D) None of these
R% = 2/10 = 20%
CI for 2 yrs at 20% =
20+20+20*20/100 = 44%
So, P : CI = 100 : 44 = 25 :
11
If the compound interest on a sum for 2 years at 12.5% per annum is Tk.510, the st
1 -yr : 2nd –yr = 8 : 9
simple interest on the same sum at the same rate for the same period of time is:
Now, (8+9) i.e. 17 ≡ 510
117.
[BB-AD – 2014] Then, (8+8) i.e. 16 ≡ 480
(A) Tk.400
(B) Tk.450
(C) Tk.460
(D) Tk.480
2
hw` evwl©K 16 /3% nv‡i 3 eQ‡i ‡Kv‡bv cwigvb UvKvi Pµe…w× my` 1270 UvKv nq, Z‡e H cwigvb
118. UvKvi H GKB mg‡q Ges GKB nv‡i mij my` n‡e (K) 1080 UvKv
(L) 2100 UvKv
(M) 2160 UvKv
(N) ‡Kv‡bvwUB bq
16(2/3) = 1/6; P = 63 = 216
36 + (36+6) + (36+6+6+1) =
127
Now, 127 is 1270
Then, 108 is 1080 [Ans. A]
Tk.500 is deposited in a savings account which pays 7% annual interest compounded
semi-annually. To the nearest Taka, how much is in the account at the end of the
year?
[Rupali Bank (Off.-Cash) – 2018 (AF)]
(A) 542
119.
(B) 536
(C) 512
(D) 524
Tk.5000 is deposited in a savings account which pays 7% annual interest compounded
semi-annually. To the nearest Taka, how much is in the account at the end of the
year?
[BDBL-(SO) – 2017 (AF)]
(A) 5423
(B) 5356
(C) 5122
(D) 5247
Upgrade yourself; it saves a lot of extra effort
12
Simple & Compound interest
The difference between the compound interest and simple interest on a certain
amount of money at 5% per annum for 2 years is Tk.15. Find the principal amount.
120.
[National Bank-PO – 2015]
(A) Tk.4500
(B) Tk.5000
(C) Tk.6000
(D) Tk.7500
The difference between the compound interest (compounded annually) and the simple
interest on a sum of Tk.5000 at a certain rate of interest for 2 years is Tk.72. The rate
121. of interest per annum is:
(A) 5%
122.
(B) 6%
(C) 10%
(D) 12%
4% nvi gybvdvq ‡Kvb UvKvi 2 eQ‡ii gybvdv I Pµe…w× gybvdvi cv_©K¨ 1 UvKv n‡j, g~jab KZ?
P×(4/100)2 = 1
P = 625
D₂ = P×R^2/100^2
Find the interest rate where difference between the compound and simple interest
= 20000×R^2/100×100 =
123. on a principal of Tk.20000 for a 2 years period is Tk.392.
392
[BRTC-AD-Technical – 2019 => R^2 = 392/2 = 196
So, R = √196 = 14%
S.I. and C.I. on a certain sum of money for 2 years are Tk.50 and Tk.51 respectively.
124. Then find the sum?
(A) Tk.500
(B) Tk.625
(C) Tk.750
(D) Tk.1000
125.
SI and CI on a certain sum in 2 years are Tk.200 and Tk.220 respectively. Find the
rate of interest and principal.
126. The C.I. on a sum of at 10% p.a. for the second year is Tk.220. Find the sum.
SI per yr = 50/2 = 25
Diff. of CI & SI = 51-50 = 1
So, P = 1×25×25 = 625
SI per yr = 200/2 = 100
Diff. of CI & SI = 220-200 =
20
R% = 20%; P = 20×5×5 =
500
10% = 1/10
CI for 2nd yr => (10+1) = 11
Now, 11 ≡ Tk.220
So, 100 ≡ 100*220/11 = 2000
If a certain sum of money at Compound Interest becomes 1.44 times of itself in 2
127. years, find rate %.
(A) 10%
(B) 12%
(C) 15%
(D) 20%
If the amount is 2.25 times of the sum after 2 years at compound interest (compound
annually), the rate of interest per annum is:
128.
(A) 15%
(B) 25%
(C) 45%
(D) 50%
(E) None of these
A sum of money becomes 1.331 times in 3 years compound interest. The rate of
interest is:
129.
(A) 7.5%
(B) 8%
(C) 10%
(D) 50%
(E) None of these
The difference between compound interest and simple interest on a sum for 2
years at 10% per annum, when the interest is compounded annually is Tk.16. If
130. the interest were compounded half-yearly, the difference in two interests would be
(A) Tk.24.81
(B) Tk.26.90
(C) Tk.31.61
(D) Tk.32.40
A sum of money placed at compound interest doubles itself in 4 years. In how many
years will it amount to 8 times itself?
[7 Banks & FI’s –SO – 2021 (AF)]
131.
(A) 12 years
(B) 8 years
(C) 16 years
(D) 64 years
T is 2 yrs, so taking square
root: P : A = √1 : √2.25
= 1 : 1.5 = 2 : 3
So, R% = ½ = 50%
T is 3 yrs, so taking cube
root: P : A = ∛1 : ∛1.331
= 1 : 1.1 = 10 : 11
So, R% = 1/10 = 10%
Here, P =
16×100×100/(10×10) = 1600
Now, 5% of 1600 = 80
5% of 80 = 4
5% of 4 = 0.2
5% of 0.2 = 0.01
So, Req. Diff. = 4×6 + 0.2×4 +
0.01×1 = 24.81
1-2-4-8
8 = 23
S, 4×3 = 12 yrs
Upgrade yourself; it saves a lot of extra effort
13
Simple & Compound interest
A sum of money at compound interest amounts to thrice itself in 3 years. In how many
132. years will it be 9 times itself?
(A) 18
(B) 12
(C) 10
(D) 9
(E) 6
133. A sum becomes twice in 5 years at CI. In how many years it will become 8 times?
8 = 23
So, 5×3 = 15 yrs
‡Kv‡bv cwigvb UvKv Pµe…w× my‡` ivL‡j 5 eQ‡i wظb nq| IB GKB cwigvb UvKv GKB Pµe…w×
134. my‡`i nv‡i 4 ¸b n‡e (K) 7 eQ‡i
(L) 10 eQ‡i
(M) 15 eQ‡i
(N) 20 eQ‡i
A sum of money compounded annually doubles itself in 15 years. In how many
Now,
years will it become 8 times?
[PKB-Officer – 2021, written] ⇒
135. Amount, A =
, [where P = principal, R = Rate of interest and t = time]
ATQ,
So,
= 2P
So,
= 8P
3
=8=2
=
∴ t = 15×3 = 45 years
[Ans.]
=2
A finance company declares that, at a certain compound interest rate a sum of money
deposited by anyone will become 8 times in 3 years. If the same amount is deposited at
136.
the same compound rate of interest, then in how many years will it become 16 times?
[Combined 8 Banks & FI’s (SO) — written -2019]
137.
If a sum of Tk.8000 is lent for 20% per annum at compound interest, then the amount
will be Tk.13824 in –
[Premier Bank – TJO – 2020]
(A) 1 yr
(B) 2 yr
(C) 3 yr
(D) 4 yr
At 20%, P:A = 100:120 = 5:6
Now, 8000:13824 = 125:216
Since, 125:216 = 53 : 63, so the
time is 3 yrs
Alternate Approach:
8000×(6/5) = 9600, Again,
9600×(6/5) = 11520; Further,
11520×(6/5) = 13824
So, required time = 3 yrs
The ratio of two amounts is 4:5. If they are lent out at compound interest for 2 years 4×(1+R/100)² = 5×(1+R/100)
and 1 year respectively, then the equal amount is received. Find the rate of interest => 1 + R/100 = 5/4
=> R = 25%
138. per annum.
(A) 30%
(B) 25%
(C) 20%
After 1 yr, 4 becomes 5
So, R% = (5-4)/4 = 1/4 = 25%
(D) 16%
139.
GKB nvi gybvdvq ‡Kv‡bv g~ja‡bi GK eQiv‡šÍ Pµe…w× g~jab 6500 UvKv I `yB eQiv‡šÍ Pµe…w×
g~jab 6760 UvKv n‡j, g~jab KZ?
140.
At compound interest rate a sum becomes Tk.2000 in 2 years and Tk.2500 in 4 years.
Find the Principal and Rate of interest.
P/6500 = 6500/6760
So, P = 6500*6500/6760 =
6250 (Ans.)
If the compound interest of a certain sum of money for two successive years be Tk.225
225 : 238.50 = 450:477 =
and Tk.238.50. What is the rate of interest per annum?
50:53
141.
[PKB-EO-Cash – 2019 (AUST)] So, R% = (3/50)×100 = 6%
(A) 5%
(B) 6%
(C) 7%
(D) 10%
An amount of Tk.10,000 becomes Tk.20,736 in 2 years. If the rate of interest is
compounded half yearly, what is the annual rate of interest?
142. (A) 25% (B) 20%
(C) 40%
(D) 30%
Principal : Amount = 10000 : 20736 = 625 : 1296
In 2-year time period, there are 4 cycle of half-year.
So, taking fourth-root, ∜625 : ∜1296 = 5 : 6
Therefore, half-yearly
increment = (6-5)/5 = 1/5 or
20%
So, annual rate of interest =
(2×20%) = 40%
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14
Simple & Compound interest
evwl©K kZKiv 10% nv‡i 1000 UvKvi 2 eQi ci mij I Pµe…w× gybvdvi cv_©K¨ KZ?
(39 BCS; Sub-Asstt. Engr.-Dhaka Wasa - 2020)
143.
(K) 10 UvKv
(L) 11 UvKv
(M) 11.5 UvKv
(N) 12 UvKv
10% of 10% of 1000
= 1% of 1000 = 10 (Ans.)
evwl©K kZKiv 10 UvKv gybvdvq 3000 UvKvi 2 eQ‡ii mij gybvdv I Pµe…w× gybvdvi cv_©K¨ KZ
[RAKUB-Officer – 2015] 1% of 3000 = 30 (Ans.)
144. n‡e?
(K) 30 UvKv
(L) 50 UvKv
(M) 60 UvKv
(N) 100 UvKv
The difference in taka between simple and compound interest at 5% annually on a
[Combined 5 Banks–(Officer) – 2018 (AF)]
145. sum of Tk.2000 after 2 years is –
(A) 5
(B) 50
(C) 20
(D) 200
The difference in taka between simple and compound interest at 5% annually on a
[BB-Officer – 2019; Rupali– Officer – 2019 (AF)]
146. sum of Tk.5000 after 2 years is –
(A) 12.5
(B) 25
(C) 50
(D) 500
The difference between simple and compound interest at 5% annually on a sum of
[PKB-Officer – 2021]
147. Tk.10000 at the end of 2 years is –
(A) Tk.25
(B) Tk.50
(C) Tk.100
(D) Tk.250
evwl©K kZKiv 10 UvKv gybvdvq 5000 UvKvi 3 eQ‡ii mij gybvdv I Pµe…w× gybvdvi cv_©K¨ KZ
[RAKUB-Officer – 2015; Class-8 (E-2.2)] 3.1% of 5000 = 155
148. n‡e?
(K) 153 UvKv (L) 155 UvKv (M) 157 UvKv (N) 158 UvKv
149.
5% nvi gybvdvq 8000 UvKvi 3 eQ‡ii mij I Pµe…w× gybvdvi cv_©K¨ KZ ?
The compound interest on Tk.10,000 for 4 years @ 5% per annum will be
[BB-AD – 2006]
150. approximately –
(A) 2000
(B) 2025
(C) 2050
(D) 2100
(E) 2150
151.
The compound interest on Tk.10,000 in 2 years at 20% per annum, the interest being
compounded half-yearly, is:
(A) Tk.14641
(B) Tk.14000
(C) Tk.4641
(D) Tk.3861
What will be the difference between simple and compound interest at 10% on a sum
of Tk.1000 after 4 years?
152.
[BB-AD – 2018 (AF); Agrani –SO-Auditor – 2017; BKB – Cash – 2017]
(A) Tk.31.90
(B) Tk.32.10
(C) Tk.44.90
(D) Tk.64.10
What will be the difference between simple and compound interest at 10% on a
sum of Tk.5000 after 5 years?
[PKB-Cash – 2021]
(A) 45
(B) 152
(C) 252
(D) 552
153.
Effective R% in CI for 5 time-cycle at 10% p.a. = 61.051%
And, Effective R% in SI for 5 time-cycle at 10% p.a. = 5*10 = 50%
So, required difference = 11.051% of 5000 = 552.55
5% of 8000 = 400;
5% of 400 = 20;
5% of 20 = 1.
So, Diff. = 3×20+1×1 = 61
[Ans. E]
R% = yearly 20%
So, half-yearly = 20/2 = 10%
Effective R% in CI for 4 timecycle at 10% p.a. = 46.41%
So, required CI = 46.41% of 10000
= 4641
Effective R% in CI for 4 timecycle at 10% p.a. = 46.41%
And, Effective R% in SI for 4
time-cycle at 10% p.a. = 4*10 =
40%
So, required difference = 6.41% of
1000 = 64.10
10% of 5000 = 500
10% of 500 = 50
10% of 50 = 5
10% of 5 = 0.5
10% of 0.5 = 0.05
Ratio for 5 times compounding =
5:10:10:5:1
So, Total CI = 500*5 + 50*10 +
5*10 + 0.5*5 + 0.05*1 = 3052.55
And, total SI for 5 yrs at 10% p.a.
= 5000*50% = 2500
So, required difference = (3052.55
– 2500) = 552.55
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15
Simple & Compound interest
154.
A person takes a loan of Tk.200 at 5% simple interest. He returns Tk.100 at the
end of 1 year. In order to clear his dues at the end of 2 years, he would pay:
(A) Tk.105
(B) Tk.110
(C) Tk.115
5% of 200 = 10
(200 – 100) = 100
5% of 100 = 5
So, 100 + 10 + 5 = 115
Note: In case of compounded
interest: 5% of 110 = 5.5
So, 100 + 10+5.5 = 115.5
(D) Tk.115.50
155.
What annual installment will discharge a debt of Tk.1092 due in 3 years at 12%
simple interest?
156.
What equal installment of annual payment will discharge a debt which is due as
Tk.848 at the end of 4 years at 4% per annum simple interest?
157.
What annual payment will discharge a debt of Tk.6450 due in 4 years at 5% simple
interest
100 + 104 + 108 + 112 = 424
424 is 848
100 is 200
What annual installment will discharge a debt of Tk.770 due in 5 years at 5% simple
158. interest?
(A) Tk.120
(B) Tk.150
(C) Tk.140
(D) Tk.145
A person lends out Tk.9000 on the condition that the loan is payable in 10 months by
10 monthly equal installments of Tk.1000 each. Find the rate of simple interest
charged.
159.
Total amount Paid = 10*1000 = 10000
Loan amount = 9000
So, Interest paid = 10000-9000 = 1000
160.
A sum of Rs.10 is lent to be return in 11 monthly installments of Rs.1 each interest
being simple. The rate of interest is?
161.
If in the case of compound interest, the rate of interest in 1st, 2nd and 3rd year are
r₁%, r₂% and r₃% respectively, then find the amount after 3 years for taka P?
[38 BCS – Written, 2018]
Now, (9000+8000+7000+ ... +
1000)*(R/100)*(1/12) = 1000
=> 45000*(R/1200) = 1000
=> R = 1000*1200/45000
= 26(2/3)%
Tk.25000 is borrowed at CI at the rate of 3% for the first year, 4% for the second
162. year and 5% for the third year. Find the amount to be paid after 3 years.
(A) Tk.28119
(B) Tk.29118
(C) Tk.28129
(D) Tk.28117
(E) None of these
A sum of Tk.1260 is borrowed from a money lender at 10% p.a. compounded
163. annually. If the amount is to be paid in two equal annual installments, find the annual
installments.
[Basic Bank-2014]
A sum of money is borrowed and paid back in 2 annual installments of Tk.882 each
allowing 5% compound interest. The sum borrowed was –
[Janata Bank-EO – 2017]
164.
(A) Tk.1620
(B) Tk.1640
(C) Tk.1680
(D) Tk.1700
A person buys a TV worth BDT 3,90,000 with a down payment of 40,000, including
Tk.5000 as first month’s installment. How many more installments does he have to
pay, if his installments had to double after each successive payment?
165.
10000 + 20000 + 40000 + 80000 + ……… = 390000 - 40000
=> 10000 (1 + 2 + 4 + 8 + ………) = 350000
=> (1 + 2 + 4 + 8 + ………) = 35
=> 2^n – 1 = 35
=> 2^n = 36
Now, 2^5 < 36 < 2^6
So, n ≈ 6
Hence, 6 more installments
Upgrade yourself; it saves a lot of extra effort
16
Simple & Compound interest
A father has divided his property between his two sons A and B. A invests the amount
at a compound interest 8%. B invests the amount of 10% simple interest. At the end
166. of two years the profit received by B is Tk.1336 more than A. Find the amount of both
if total amount of the father is Tk.25000.
A father left a will of Tk.35 lakhs between his two daughters aged 8.5 and 16 such that
they may get equal amounts when each of them reach the age of 21 years. The original
167. amount of Tk.35 lakhs has been instructed to be invested at 10% p.a. simple interest.
How much did the elder daughter get at the time of the will?
(A) Tk.17.5 lakhs
(B) Tk.21 lakhs (C) Tk.15 lakhs (D) Tk.20 lakhs
A father left a will of Tk.16400 for his two sons aged 17 and 18 years. They must get
168. equal amounts when they are 20 years at 5% compound interest. Find the present
share of the younger son.
(21/20)*(21/20)*(21/20)*Y =
(21/20)*(21/20)*E
=> (21/20)*Y = E
=> Y : E = 20 : 21
Now, (20+21) i.e. 41 ≡ Tk.16400
Then, 20 ≡ 20*16400/41 = 8000
A father wants to invest Tk.35,300 in a bank account of his two sons whose ages are 12
years and 16 years in such a way so that, they will get equal amount at an age of 30
years at the rate of 66( ) % per annum C.I. Find the share of younger son?
(A) 7630
169.
(B) 6530
(C) 4050
(D) 4080
(E) None of these
12 to 30 ⇒ 18 yrs and 16 to 30 ⇒ 14 yrs
66( ) % = and (
) =
Now, Y’s amount after 18 yr ⇒ Y ( )
ATQ, Y ( )
= E( )
⇒Y( ) =E
⇒Y:E=
:
= 81 : 625
Here, (81+625) = 706
So, Y will get ⇒ 35500 ×
= Tk.4050
And, E’s amount after 14 yr ⇒ E ( )
Mr. X bought 400 shares of Tk.25 each at Tk.32.5. If the dividend declared is 4%,
[IBA-MBA – 1996-97]
170. what is his income on the shares?
(A) 1000
(B) 800
(C) 400
(D) 200
(E) None of these
A person lent out a certain sum on simple interest and the same sum on compound
interest at a certain rate of interest per annum. He noticed that the ratio between the
difference of compound interest and simple interest of 3 years and that of 2 years is
171.
25:8. The rate of interest per annum is –
(A) 10%
(B) 11%
(C) 12%
(B) 100/7
(C) 300/7
(D) 400/7
(E) None of these
The ratio of difference between C.l. and S.l. in 2 years and 3 years is 9:29. Find the
173. rate of interest compounded annually.
(A) 22.22%
(B) 24%
(C) 27.27%
25 = 8 + 8 + 8 + 1
So, R% = 1/8 = 12.5%
(D) 12(1/2)%
The difference of compound interest and simple interest for 3 years and for 2 years
172. are in ratio 23:7 respectively. What is rate of interest per annum (in %)?
(A) 200/7
Dividend is calculated on
face value
400×25×4% = 400
(D) 18.18%
23 = 7 + 7 + 7 + 2
So, R% = (2/7)*100 =
200/7% or 28.57%
Difference in 2 yr => 9
Difference in 3 yr =>
9+9+9+2
So, R% = 2/9 = 22.22%
evsjv‡`‡ki RbmsL¨vi ¯^vfvweK e„w×i nvi 2.0% n‡j, †`‡ki RbmsL¨v wظb n‡Z KZ eQi jvM‡e ?
174.
(K) 30 eQi
(L) 33 eQi
(M) 35 eQi
(N) 40 eQi
Rule of 70 => 70/2 = 35 yrs
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