If the selling price of a product is multiplied by 2, the resulting profit is 6 times the original profit. What is the original profit percentage?

A scientist mixes 10% water in his solution but he is not content with it so he again mixes 10% more water in the previous mixture. What is the profit percentage of the scientist if he sells it at cost price:

If a vendor sells apples at Rs 170 per kg he suffers 15 % loss. If he sells at Rs 230 per kg, then what is his profit percentage? 

Krishna 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 Krishna on the original price was 

A trader had 16 quintals of wheat. He sold a part of it at 17% profit and the rest at 27% profit, so that he made a total profit of 21%. How much wheat did he sell at 27 % profit? 

If the cost of production of an article is 2/5 of its marked retail price, If it is sold at 10 % discount then what will be profit ? 

If a man purchase 11 articles for Rs.10 and sold all the articles at the rate of 10 for Rs.11, the profit percentage will be.

An article was sold for Rs.4000. Had a discount of 10% was being offered, the profit would have been 20%. The cost price of the article was: