A sum of Rs.4700 is doubled in 6 yeaRs. under simple interest at a certain rate of interest. The interest is Rs.____________.

A sum of Rs 4200 becomes Rs 5082 in 3 years rate simple interest. What is the rate of interest per annum?

A sum amounts to Rs. 5600 in 4 years and Rs. 6400 in 6 years at a certain rate of simple interest. Find the rate of interest per annum and the sum.

A sum of Rs. 16000 earns a simple interest of Rs. 2560 in 2 years. Find the rate of interest per annum.

A sum of Rs. 1600 gives a simple interest of Rs. 252 in 2 years and 4 months. The rate of interest per annum is: