Rachna borrowed a certain sum at the rate of 15% per annum. If she paid at the end of two years Rs. 1290 as interest compounded annually, find the sum she borrowed.
A and B borrowed Rs. 60000 and Rs. 50,000 respectively for a period of 3 years. A paid simple interest at a rate of 10% per annum while B paid compound interest at the rate of 10% per annum compounded annually. Who paid more and by how much?