The amount at compound interest which is calculated yearly on a certain sum of money is ₹1250 in one year and ₹1375 after two years. Calculate the rate of interest.

The simple interest on a certain sum for 3 years is ₹225 and the compound interest on the same sum at the same rate for 2 years is ₹153. Find the rate of interest and principal.

A sum of money is lent out at compound interest for two years at 20% p.a., C.I. being reckoned yearly. If the same sum of money is lent out at compound interest at same rate percent per annum, C.I. being reckoned half-yearly, it would have fetched ₹482 more by way of interest. Calculate the sum of money lent out.