Find the amount and the compound interest on ₹2000 in 2 years if the rate is 4% for the first year and 3% for the second year.

Find the compound interest on ₹3125 for 3 years if the rates of interest for the first, second and third year are respectively 4%, 5% and 6% per annum.

What sum invested at 4% per annum compounded semi-annually amounts to ₹7803 at the end of one year?