Rajan purchased a purse at 25% discount on its marked price but sold it at the marked price. Find the gain percent of Rajan on this.

A vendor bought oranges at 20 for Rs.56 and sold them at Rs.35 per dozen. Find his gain or loss per cent?

By selling 144 hens, swarn lost the selling price of 6 hens. Find her lost percent.

The question is - A grocer purchased 200kg of rice at Rs. 25 per kg. He sold 80kg of at a gain of 10% and 40kg at a loss of 4%. At what rate per kg should he sell the remainder to gain 8% on his total investment?

There are 120 girls and 57 boys in a school. If 5% of the girls leave and no new pupils are admitted, what percentage of the whole school will be boys?