Gopal has a cumulative deposit account and deposits ₹ 900 per month for a period of 4 years. If he gets ₹ 52020 at the time of maturity, find the rate of interest.

Mr. Britto deposits a certain sum of money each month in a Recurring Deposit Account of a bank. If the rate of interest is of 8% per annum and Mr. Britto gets ₹ 8088 from the bank after 3 years, find the value of his monthly instalment.

Katrina opened a recurring deposit account with a Nationalised Bank for a period of 2 years. If the bank pays interest at rate of 6% per annum and the monthly instalment is ₹ 1000, find the :

(i) interest earned in 2 years

(ii) maturity value.