Question

A certain sum of money doubles itself in 8 years .In how much time will it become 4 times of itself at the same rate of interest?

Answer 1

Direct method

1-----------2 in 8 yr

In 8yr we get interest =1

Now

1------------4
Interest =4-1=3

If we get 1 as interest in 8 year then we get 3 in 24yr

This is ur ans hope it will help you in case of any doubt comment below