What sum of money will amount to ₹ 5445 in 2 years at 10% per annum compound interest ?

On what sum of money will the compound interest for 2 years at 5 per cent per annum amount to ₹ 768.75 ?

At what rate per cent per annum will ₹ 6000 amount to ₹ 6615 in 2 years when interest is compounded annually ?

What principal will amount to ₹ 9856 in two years, if the rates of interest for successive years are 10% and 12% respectively?