A sum of money doubles itself in 3 years. At same rate of simple interest, for a period of 9 years, how many times will the sum become?

A sum becomes 14 times of itself in 15 years at the rate of simple interest per annum. In how many years will the sum becomes 92 times of itself?

A sum of money becomes 8/5 of itself in 5 years at a cartain rate of simple interest find the rate of interest

A sum of money becomes (7)/(6) of itself in 3 years at certain rate of simple interest. The rate per annum is