What will be the difference between the compound interest and simple interest at the rate of 5% per annum on an amount of Rs 4000 at the end of 2 year?

A person lends 40 % of his sum of money at 15 % per annum, 50 % of rest at 10 % per annum and the rest at 18 % per annum rate of interest. What would be the annual rate of interest, if the interest is calculated on the whole sum? 

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