Question

a man invested some money and it became double in 6 years. find the sum

Answer 1

let the sum of money that's principal be = X
time =6 years
amount after 6 years becomes double =2 x
therefore , simple interest = amount - principal
=2x - X = X
Rate per annum
= SI X 100/ P x T = X x 100
=X x 6
= 100/6
= 50/2
= 16.66 percent ( approx)