A cow was sold at 8% profit. If it were bought at 20% less and sold at 40% profit, then the owner would gain ₹ 640 more. Find the initial cost price of the cow.

The reduction of Rs . 12 in the selling price of an article will changes 5 % gain into  $$ 2{1\over 2}\% $$ loss . The cost price of the article is 

If shopkeeper sold the mobile for Rs.15000 and then he gets some loss. If he sold the same mobile at Rs.19200 and then he gets profit is double of loss. Find the cost price of the mobile?

Due to increase in the value of eggs by 20 percent, two eggs started getting less at Rs. 24. The current price per dozen of eggs.

A trader had 2000 kgs of rice. He sold a part of it at 10 % profit and the rest at 16 % profit so that he made a total profit of 14.2%. How much rice (in kg) did he sell at 10 % profit? 

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:

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? 

An article is sold at a loss of 40%. The nominal amount of loss is approximately what percentage of the selling price of the article?