Question

A sum of money when kept at simple interest doubled in eight years four months . If the rate of interest is doubled , in which year the same sum becomes twice of itself under simple interest ? Please explain step by step

Answer 1

let the sum be x,rate of interest be r and time will be 25/3 years
interest will also be x so that the amount is double the sum i.e. 2x
now put x*r*25/100*3=x
rate of interest r = 12%
next double r will be 24%,sum=x,let time be t
again interest =x (bcoz amount =2x)
put all these again in the formula as
x*24*t/100=x
you will get t=25/6 years(i.e. 4 years 2 months)