A man gain 15% by selling a calculator for a certain price. If he sells it at the triple price, then what will be the profit percentage?

A phone is sold for Rs. 860 at a loss of 20% for how much should it be sold gain 10%?

The price of 6 pencils is Rs. 30 and that of 12 pens is Rs. 120. What is the average price of 50 pencils and 50 pens?

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

A & B jointly made a profit of Rs. 1650 and they decided to share it such that 1/3 of A's profit is equal to 2/5 of B's profit. Then profit of B is 

A store sells a watch for a profit of 25% of the cost. Then the percentage of profit against selling price is-

Mohan bought 25 books for Rs. 2,000 and sold them at a profit equal to the selling price of 5 books. The selling price of 1 book is: