Question

What sum of money invested at 7.5% per annum will yield same simple interest in 4 years as rs5000 yields in 5 years at 9% per annum?

Answer 1

We'll have to answer the compound interest problem first.
total = princ*(1+rate)^years
total = 5,000 * 1.09 ^5
total = 5,000 * 1.5386239549
total = 7,693.12

For the simple interest problem, we need to know the money needed to be invested for 5 years to yield $7,693.12.
princ + .09 * 5 * princ = 7,693.12
princ + .45*princ = 7,693.12
princ. = 7,693.12 / 1.45
= 5305.60
5305.60*.09 = 477.50 interest per year
* 5 years = 2,387.50

5,305.60 plus
2,387.50 equals
7,693.10 Total