Question

An amount of money double itself in 10 years. What is the rate of intrest ?

Answer 1

Let the sum of money that's principal be x.

Time = 10 years

Amount after 10 years becomes double = 2x

Therefor, Simple Interest = Amount - Principal = 2x-x = x

Rate per annum = SI×100/ P×T = x×100/x×10 = 100/10 = 10%