If the cost price of 28 items is equal to the selling price of 21 items, what is the profit percentage?

Anil bought two articles A and B at a total cost of ₹ 10,000. He sold the article A at 15% profit and the actacle B at 10% loss. In the whole deal, be made no profit or no loss. Find the selling price of the article A.

If apples are bought at the rate of 30 for a rupee. How many apples must be sold for a rupee to gain 20%?   

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 & 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 

Krishnan bought a camera and paid 20% less than its original price. He sold it at 40% profit on the price he had paid. The percentage of profit earned by Krishnan on the original price was

By what fraction selling price ( S.P. ) must be multiplied to get the cost price ( C.P. ) if the loss is 20%?