The difference between the compound interest for 1 year, compounded half-yearly and the simple interest for 1 year on a certain sum of money at 10% per annum is ₹ 360. Find the sum.

At what rate per cent per annum compound interest will ₹ 6,250 amount to ₹ 7,290 in 2 years?

A certain sum of money amounts to ₹ 7,260 in 2 years and to ₹ 7,986 in 3 years, interest being compounded annually. Find the rate per cent per annum.