Question

how to do this question

At what rate percent per year will a sum double itself in 25/4 years

Answer 1

Let to be Principal 2y RS
Time=25/4 year
Amount=y
Interest=P-A=2y-y=y
S.I=P*R*T/100
Y=Y*R*25/4/100
R=100*x/(4*25x)
=Rate=16%

Answer 2

Let P = x
SI = x
A = 2x
T = 25/4
R = ?

R = SI * 100/P *T
= x * 100* 4 / x * 25

x and x will cut and 25 *4 = 100
4 * 4
= 16 %