Question

A certain sum of money doubles itself at simple interest in 8years .In how many years will it be three times at the same rate?

Answer 1

principal =x
Interest =x
x= x*8*r/100
r=100/8
--------------=
2x= x*n*100/8 *1/100
2=100n/800
1600=100n
n= 16 years