If the amount received at the end of 2nd and 3rd year as Compound Interest on a certain Principal is Rs 24200, and Rs 26620 respectively, what is the rate (in %) of interest? 

A sum amounts to ₹ 6480 in 4 years and ₹ 9600 in 8 years when it is compounded annually. Find the sum?

A bank pays half-yearly compound interest at the rate of 5% p.a. . A person deposited Rs 1600 on January 1 and a similar amount on July 1 . Explain how much interest will be paid by the bank at the end of the year.

Interest earned by Ramesh on Rs.10,000 for 2 years at R% p.a. simple interest is how much more/less than interest earned by him on Rs. 8000 for 2 years at (R+10)% p.a. compounding annually. If Rs. 2000 is invested at 2R% p.a. simple interest for a year, then it would fetch an interest of Rs.400.

The difference between CI and SI on a sum of money for 3 years at 5% per annum is Rs.61. Find the sum.