A certain amount of money deposited in a bank becomes Rs.1008 in 2.5 years and Rs.1164 in 3.5 years. Find the amount deposited and the rate of interest per annum.

The deposit is Rs. 800 at 13% per year.

Under simple interest the amount grows by an equal sum each year.

Each year adds Rs. 104 of interest to the deposit.

Principal + 2 years of interest = 800 + 208 = 1008.

Rate = 104 / 800 x 100 = 13%, and 800 + 364 = 1164 later.