Question

A sum of money double itself in 5 year how much how many years will it take to four times

Answer 1

Answer: 10 years

Let the initial sum of money equals to rupees x

then after 5 years sum of money equals 2 X rupees

And after another 5 years sum of money equals 4x rupees

So a total of 10 years will be taken to make the sum of money 4 times.