A Sum of Rs 7140 is to be divided between Anita and Aman who are respectively 18 and 19 year old, in such a way that if there shares will be invested at 4% per annum at compound interest, they will receive equal amounts on attaining the age of 21 year. The present share of Anita is -

Let Anita's share = x, Aman's share = 7140 - x. Anita invests for 3 years (18 to 21), Aman for 2 years (19 to 21). At 4% CI with equal maturity amounts: x(1.04)^3 = (7140 - x)(1.04)^2. Divide both sides by (1.04)^2: x(1.04) = 7140 - x. So 1.04x + x = 7140, 2.04x = 7140, x = 7140/2.04 = 3500. Anita's present share is Rs 3500.