A certain sum of money at a certain rate doubles itself in 9 years, then in how many years it will become the same sum will be 5 times of itself?

The difference between simple interest and compound interest on a certain sum at $$ 12{1\over2}$$ % for 3 years is Rs 125. Find the sum.

If the difference of the compound interest and the simple interest on a sum of money for 3 years is Rs. 186. Find the sum of money, if the rate of interest in both cases be 10 % 

On a certain sum of money, the difference between the compound interest for a year, payable half yearly, and the simple interest for a year is Rs. 56.If the rate of interest in both the cases is 16 %, then the sum is 

If the amount is $$3{3\over 8}$$ times the sum after 3 years at compound interest compounded annually, then the rate of interest per annum is 

The sum for 2 years gives a compound interest of ₹ 3225 at 15 % rate. Then sum is 

At what percent per annum will Rs. 3000 amounts to Rs. 3993 in 3 years if the interest is compounded annually?  

In how many years will be Rs. 2,000 amounts to Rs.2,420 at 10% per annum compound interest ?