Simple interest accrued on an amount in 8 yr @ 12 % per annum is Rs 5520 What is the principal amount ?

Equal sum of money are lent to X and Y at 7.5 % per annum for a period of 4 years and 5 years respectively. If the difference in interest, paid by them was 150, the sum lent to each was 

A sum of ₹ 400 amounts to ₹ 480 in 4 years. What will it amount to if the rate of interest is increased by 2 %? 

Out of ₹ 20, 000 Narendra gives some amount on loan at simple interest rate 8 % per annum and rest amount at simple interest rate 4 / 3 % per annum. At the end of year he earns ₹ 800. The amount given at 8 % rate will be – 

A sum of money was lent at simple interest at certain rate for 3 years. Had it been lent at 2.5 % per annum higher rate, it would have fetched ₹ 540 more. The money lent was