Question

a sum of money invested at compounded intrest for 9 month at 20% per annum .when the intrest is compouded half yearly .if the intrest were compouded quarterly it would have fetches rupees 210 more than in previous case find the sum

Answer 1

interest rate for quarter =5%. When compounding quarterly amount=P*(1.05)^3 for 3 quarters. When compounded half yearly rate of interest is 10% but will be paid only once. Hence in latter case amt=P*1.1. The diff of amounts=diff of interests=0.057625P. Equate to 21 0 gives P=3644