A sum of money at simple interest amounts to Rs. 696 in 2 years and Rs. 840 in 5 years . What will be the sum ?

If a certain sum of money at simple interest amounts to Rs. 5184 in 2 years and to Rs. 5832 in 3 years, what is the sum and the rate of interest?

A sum of money at simple interest amounts to Rs 800 in 2 years and to Rs 1200 in 6 years. The sum is……………

A sum of money on compound interest amount to Rs. 9680 in 2 years and to Rs. 10648 in 3 years. What is the rate of interest per annum?