Find the Interest Earned
(I= PRN)
Principal = $6000
Interest Rate = 7 % p.a.
Time period (N) = 5 years
Find the Interest (I)
R = 7 ÷ 100 = 0.07
I=PxRxN
= $6000 x 0.07 x 5
= $2100
Principal = $14000
Interest Rate = 5.5 % p.a.
Time period (N) = 6 years
Find the Interest (I)
Principal = $17000
Interest Rate = 7.2 % p.a.
Time period (N) = 8 years
Find the Interest (I)
Total Amount A = Repayment Amount x
Number of Repayments
Interest = A ‐ P
John buys furniture on terms. The value
of the furniture is $12,500. If he repays
$505 per month over 3 years, what is the
total amount he repays and what is the
total interest he pays?
P = $12,500, Repayments = $505 / month
Number of repayments = 3 years x 12
= 36
A = 36 x $505
= $18,180
What is the annual interest rate that John
pays on his furniture purchase to the nearest
percent? (See 2nd column)
P = $12,500
Interest (over 3 years) = $5,680
I for 1 year = $5,680 ÷ 3
= $1893.33
I=A–P
= $18,180 ‐ $12,500
= $5,680
Isobel buys a home entertainment
system on terms. The value of the system
is $6,000. If she repays $235 per month
over 4 years, what is the total amount
she repays and what is the total interest
she pays?
What is the annual interest rate that Isobel
pays on her furniture purchase to the nearest
percent? (See 2nd column)
Curtis buys laundry appliances and a
fridge on terms. The value of the white
goods is $9,800. If he repays $425 per
month over 2.5 years, what is the total
amount he repays and what is the
interest he pays?
Find the Interest Rate
𝐼𝑛𝑡𝑒𝑟𝑒𝑠𝑡 𝑅𝑎𝑡𝑒
$1893.33
$12500
= 15.1 %
= 15 %
100 %
What is the annual interest rate that Curtis
pays on his furniture purchase to the nearest
percent? (See 2nd column)