A retailer buys a cooler for Rs 1200 and overhead expenses on it are Rs 40. If the coller for Rs 1550, determine his profit percent.

The cost price of 10 articles is equal to the selling price of 9 articles. Find the profit percent.

A retailer buys a radio for Rs 225. His overhead expenses are Rs 15. If he sells the radio for Rs 300, determine his profit percent.

A dealer buys a wristwatch for Rs 225 and spends Rs 15 on its repairs. If he sells the same for Rs 300, find his profit percent.

Ramesh bought two boxes for Rs 1300. He sold one box at a profit of 20% and the other box at a loss of 12%. If the selling price of both boxes is the same, find the cost price of each box.