If after selling 30 pens, the seller observes the profit of sell price of 10 pens, then the profit percentage is –

The cost price of 40 oranges is equal to the selling price of 30 oranges. Find the percentage profit.

A cloth merchant on selling 33 metre of cloth obtains a profit equal to the selling price of 11 metre of cloth. The profit percentage is :

If 3 mangoes are sold for the cost price of 4, the profit percentage is -

The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25%, then the value of x is:

A man gains 20% by selling an article for a certain price. If he sells it at double the price, the percentage of profit will be