Question

Simple Interest of a Certain Sum
If a certain sum is doubled in 8 years on simple interest, in how many years will it be 4 times?

Answer 1

We are talking of simple interest.

Lets try to understand by mean of an example.

If you have Rs. 100 as the starting sum of money and it takes 8 years to double it. Now the new principle is Rs. 200 and it will take another years to double it (i.e. the amount will be Rs. 400 after the next 8 years)

We can clearly deduce that in order to increase our money 4 times, it will take us 16 years in all.