At the beginning of year 2011, a man had ₹ 22,000 in his bank account. He saved some money by the end of this year and deposited it in the bank. The bank pays 10% per annum compound interest and at the end of year 2012 he had ₹ 39,820 in his bank account. Find, what amount of money he had saved and deposited in his account at the end of year 2011 .

A sum of ₹ 16,000, invested at simple interest, amounts to ₹ 22,400 in 4 years at a certain rate of interest. If the same sum of money is invested for 2 years at the same rate of interest, compounded p.a., find the compound interest earned.

The cost of a car, purchased 2 years ago, depreciates at the rate of 20% every year.If its present value is ₹ 2,52,480, find:

(i) its purchase price.

(ii) its value after 1 year.

If x² + y² = 37 and xy = 6; find :

(i) x + y

(ii) x - y

(iii) x² - y²