What is compound interest

What is the compound interest on a sum of Rs. 13,000 at 15% p.a .in 2 yers ,if the interest in compounded 8- monthly ?

What is the compound interest on a sum of Rs 13,000 at 15% p.a. in 2 years, if the interest is compounded 8- monthly?

A sum of Rs. 3000 is invested on compound interest (compounded anually) at the rate of interest 20% per annum What is the compound interest for 2 years ?

What is the compound interest (in Rs) on a sum of Rs 15000 for 2 years at the rate of 10% per annum compounded annually?

What is the compound interest on Rs. 1600 at 25 % per annum for 2 years compounded annually ?

What is the compound interest on Rs. 38000 at 20% per annum for a period of (3)/(2) years compounded semi-annually ?