Question

A man opened a recurring deposit account in a bank. He deposited Rs. 2500 per month for two
years. At the time of maturity, he received Rs. 67500.

Find
i. The total interest earned by him.
ii. The rate of interest per annum.​

Answer 1

Answer:

(i) Monthly installment = Rs. 2500

n =2 years = 24 months, Amount deposited = 2500 cross times 24 = Rs. 60000

Maturity value = Rs. 67,500

Interest on his deposit = Rs. (67500 - 60000) = Rs. 7500

(ii) Now, Interest =begin mathsize 12px style fraction numerator straight n left parenthesis straight n plus 1 right parenthesis over denominator 2 end fraction cross times fraction numerator Installment space cross times space Rate over denominator 100 cross times 12 end fraction end style

begin mathsize 12px style rightwards double arrow 7500 equals fraction numerator 24 cross times 25 over denominator 2 end fraction cross times fraction numerator 2500 cross times space Rate over denominator 100 cross times 12 end fraction end style

Rate = begin mathsize 12px style fraction numerator 7500 cross times 100 cross times 24 over denominator 24 cross times 25 cross times 2500 end fraction end style= 12% p.a.

Rate of interest is 12% p.a.