Question

The simple interest on a certain sum of money and at 10% per annum is Rs. 6,000 in 2 years, Find:

1. the sum.
2. the amount due to the end of 3 years and at the same rate of interest compounded annually.
3. the compound interest earned in 3 years. 

Answer 1

(i) I = Rs. 6,000, T = 2 years and R = 10%
∴ P = `["I" xx 100]/["R" xx "T"] = [ 6,000 xx 100]/[10 xx 2]` = Rs.30,000

(ii) P = Rs. 30,000, n = 3 years and r = 10%

A = `P( 1 + r/100)^n`

= `30,000( 1 + 10/100)^3`

= `30,000(11/10)^3`

= `30,000 xx 11/10 xx 11/10 xx 11/10`

= Rs. 39,930

(iii) C.I. earned in 3 years = A - P = Rs. (39,930 - 30,000) = Rs. 9,930.