Question

A trust caring for handicapped children gets Rs. 30,000 every month from its donors. The trust spends half of the funds received for medical and educational care of the children and for that it charges $2\%$ of the spend amount from them, and deposits the balance amount in a private bank to get the money multiplied so that in future the trust goes on functioning regularly. What per cent of interest should the trust get from the bank to get a total of Rs. 1,800 every month?

Answer 1

For the first 15000, the earnings are $2\%$ of spent amount = $2\%$ of 15000 = 300
The rest 15000 is deposited in a bank.
Find the rate of interest that fetches you (2000-300)= 1700 as interest.