What sum would amount to Rs 17,280 in 3 years, at an interest of `20%` per annum rate, interest compounded annually?

A certain sum amounts to Rs.280900 in 2 years at 6% per annum, interest compounded annually. The sum is :

What will be the compound interest on Rs 15,625 for 3 years at 8% per annum, if the interest in compounded annually?

What will be the compound interest on Rs. 15625 for 3 years at 8% per annum, if the interest is compounded annually ?

A sum of Rs. 5120 amounts to Rs. 7290 in 3 years at compound interest. Find the rate of interest per annum.