The City School
Prep Girls North Nazimabad
Class 8 Work Sheet Mathematic
Simple interest
While solving the questions on simple interest worksheet we need to remember;
the formula for calculating simple interest (S.I.) = (P × R × T)/100 and, formula for calculating
amount (A) = P + I
1. How much interest does a $318 investment earn at 9% over one year?
4. If the balance at the end of eight years on an investment of $630 that has been invested at a
rate of 9% is $1,083.60, how much was the interest?
2. What sum would yield an interest of $36 in 3 years at 3% p.a.?
3. At what rate per cent per annum will $250 amount to $330 in 4 years?
4. At what rate per cent per annum will $400 yield an interest of $78 in 11/2 years ?
5. In what time will $400 amount to $512 if the simple interest is the calculated at 14% p.a.?
6. A sum amount to $2400 at 15% simple interest per annum after 4 years. Find the sum.
7. Ken borrowed $2000 from Sam at 8% per annum. After 6 year he cleared the amount by
giving $2600 cash and a watch. Find the cost of the watch.
8. In how many years will $400 yield an interest of $112 at 14% simple interest?
9. In how many years will $12000 yield an interest of $13230 at 10% simple interest?
10. In how many years will $600 double itself at 10% simple interest?
11. At what rate of simple interest will $5000 amount to $6050 in 3 years, 4 months?
12. At what rate of simple interest will the sum of money double itself in 6 years?
13. Find the simple interest at the rate of 5% p.a. for 3 years on that principal which in 4 years, 8
months at the rate of 5% p.a. gives $1200 as simple interest.
14. At what rate per cent per annum will $4000 yield an interest of $410 in 2 years?
15. Simple interest on a certain sum is 16/25 of the sum. Find the rate per cent and time if both are
numerically equal. [Hint: (T = R), P = x, S.I. = 16/25 x]
Answer
DISCOUNT
4. Marked price of a shawl is $960. It was sold at a discount of 15%. Find the discount allowed
on the shawl. Also find its selling price.
5. A handbag is marked $280 and sold to the customer for $252. Find the rate of discount on the
handbag.
6. A quilt was sold for $880 after allowing a discount of 12% on the marked price. Find the
marked price of the quilt.
7. A shopkeeper offer 16% discount to the customer and still makes a profit of 20%. What is the
Cost Price of a pair of jeans marked $1190.8. What price should a trader mark on an article
which cost him $1080 so as to gain 25% after allowing a discount of 25%.
9. A shopkeeper marked his good 25% above the Cost Price and allows a discount of 16% on it.
What per cent does he gain?
2. The price of a sweater was slashed from $ 960 to $ 816 by a shopkeeper in the winter season.
Find the rate of discount given by him.
3. Find the rate of discount being given on a shirt whose selling price is $ 546 after deducting a
discount of $ 104 on its marked price.
Hint. MP = (SP) + (discount). 4. After allowing a discount of 8% on a toy, it is sold for $ 216.20.
Find the marked price of the toy.
5. A tea set was bought for $ 528 after getting a discount of 12% on its marked price. Find the
marked price of the tea set.
6. A dealer marks his goods at 35% above the cost price and allows a discount of 20% on the
marked price. Find his gain or loss per cent.
7. A cell phone was marked at 40% above the cost price and a discount of 30% was given on its
marked price. Find the gain or loss percent made by the shopkeeper.
8. A dealer purchased a fan for $ 1080. After allowing a discount of 25% on its marked price, he
gains 25%. Find the marked price of the fan.
Answers
4. $816
5. 10%
6. $1000
7. $420
8. $1800
9. gain 5%
2. 15%
3. 16%
4. $ 235
5. $ 600
6. Gain = 8%
7. Loss = 2%
8. $ 1800
Profit and loss percentage
4. Andy purchased 120 pencils at the rate of $2 per pencil. He sold 72 of them at the rate of $2.5
per pencil and the remaining at the rate of $2 per pencil. Find his profit or loss per cent.
5. Mike sold two horses for $18000 each. On one he gained 20% and on the other he lost 20%.
Find his total gain or loss.
6. A television set was bought for $3900. $200 was spent on transportation and $900 on repair. It
was sold at a loss of 10%. Find the S.P. of television.
7. A bed sheet was sold for $483 thereby gaining 15%. Find the C.P. of the bed sheet.
8. Aaron bought an almirah for $1520 and sold it at a profit of 12 1/2 %. Find the selling price of
the almirah.
9. By selling a camera for $2400, Ron loses 4%. At what price must he sell it to gain 12 %.
10. By selling a stool for $240 a carpenter loses 20%. How much per cent would he gain or lose
by selling it for $360?
11. The selling price of 12 eggs is equal to the cost price of 15 eggs. Find the gain per cent.
12. The cost price of 10 bananas is equal to the S.P. of 12 bananas. Find the loss per cent.
Answers
4. Profit 15%
5. Loss 4 1/6%
6. $4500
7. $420
8. $1766.25
9. $2800
10. Profit 10%
11. Profit 25%
12. Loss 16 2/3%
Speed conversions
3. Express the following speed in m/sec.
(i) 36 km/hr
(ii) 90 km/hr
(iii) 144 km/hr
(iv) 7.2 km/hr
(v) 12.8 km/hr
4. Express the following speed in km/hr.
(i) 15 m/sec
(ii) 10.5 m/sec
(iii) 24 m/sec
(iv) 30 m/sec
(v) 4 ½ m/sec
Answers
3. (i) 10 m/sec
(ii) 25 m/sec
(iii) 40 m/sec
(iv) 2 m/sec
(v) 3 5/9 m/sec
4. (i) 54 km/hr
(ii) 37.8 km/hr
(iii) 86.4 km/hr
(iv) 108 km/hr
(v) 16.2 km/hr
Speed
2. Find the speed and average speed of a train which leaves Madras at 1 p.m. and reaches
Vijayawada in the same day at 9 p.m. The distance between the two stations is 432 km and the
total time for stoppage is 2 hours between these stations. Ans av speed =74km/hr
6: A vehicle travels 24 km with a constant speed of 65 km/h and another 50 km with a constant
speed of 80 km/h. What was its average speed?
5: A car travels for 1 1/2 hours km with a constant speed of 65 km/h and then travels for 45
minutes with a constant speed of 80 km/h. What distance did the vehicle cover?