The sum of the present age of a father and a son is 60 years. Five years before, the age of the father was four times that of son. What is the present age of the son ?

The profit earned by selling an item for Rs 700 is equal to the loss incurred when the same item is sold for Rs 400. What is 50% of the price of the item ?

A plot of 1200 sq ft is available for sale at the rate of Rs 240 per sq ft. If the booking amount is 15% of the total cost of the plot, then how much amount does a person need to pay to book that plot ?