Question

The simple interest on a certain sum for 8 months at 4%

Answer 1

The simple interest on a certain sum for 8 months at 4% per annum is Rs. 129 less than the simple interest on the same sum for 15 ...

Answer 2

Explanation:

The simple interest on a certain sum for 8 months at 4% per annum is Rs. 129 less than the simple interest on the same sum for 15 months at 5% per annum. ... Let sum be x. So 8 month SI will be x*.04*8/12 and for 15 months it will be x*.04*15/12 hence x*.04*15/12-x*.04*8/12=129 or 7x=129*12/.04=38700 or x=38700/7=5529.