A certain sum is lent at 5% p.a. for the first 2 years, 9% p.a. for the next 3 years and 13% p.a. for the period beyond 5 years. If the simple interest on the sum for a total period of 10 years is Rs. 8,160, then the sum (in Rs.) is:

A sum becomes 2215 of itself in 6 years at simple interest. Find the rate of interest per annum.

In how many years will a sum of ₹5,500 amount to ₹6,600 at a simple interest rate of 5% per annum?

A sum of money amounts to ₹16000 in 6 years at simple interest of 25 percent per annum. What will be the total interest for 6 years?