Naveen purchased a gas cylinder and a stove for Rs.4500. He sold the gas cylinder at a gain of 25% and the stove at a loss of 20%, still gaining 4% on the whole. Find the cost of the gas cylinder.
5 year hence, ratio of ages of A and B will be 7 : 5 and difference between their ages will be 4 years. What are present ages (in years) of A and B respectively?