Question

A sum of money invested at a certain rate of simple interest doubles itself in 10 years. In how much time will it treble itself at same rate?​

Answer 1

15 years

let money invested =500

after 10yeasr it is 1000

then in 5 years the amount will be half of the sum that is 500

so after 15 years it will be 1000+500=1500