Question

At what rate per cent per year will a sum double itself in 6and1/4 years

Answer 1

P = x
A = 2x
T = 6 1/4 years
= 25/4 years
SI = A - P
= 2x - x
= x
R = 100 * SI / P * T
= 100 * x * 4 / x * 25
= 16%