From 2008 to 2009, the sales of a book decreased by 80%. If the sales in 2010 were the same as in 2008, by what percent did it increase from 2009 to 2010?

By selling 100 pencils, a shopkeeper gains the selling price of 20 pencils, His gain percent is:

A shopkeeper bought goods for Rs. 2025. He sold $$ {1\over 5}$$ th of it at 20% profit and the remaining at the profit of 5%, the profit per cent on the whole is

A dealer bought an item at 10% discount on its original price. He sold it  at 35 % more than the original price. What percentage profit did he get?

Ram sells a car to Mohan at a profit of 16% and Mohan sells it to Shyam at a profit of 25%. How much profit% Ram would have got if he had sold the car directly to Shyam at the price Shyam bought it?

Anoop sells a book to Mayank at a profit of 20% and Mayank sells this book to Siddharth at a profit of 25%. Now Siddharth sells this book at a loss of 10% to Shishir. At what percentage loss should Shishir sells this book now so that his SP becomes equal to Anoop’s CP?

A man has 60 pens. He sells some of these at a profit of 12 % and the rest at 8 % loss. On the whole, he gets a profit 11 %. How many pens were sold at 12 % profit.

Raghu sold an article for Rs. 180 after allowing a 20% discount on its marked price. Had he not allowed any discount, he would have gained 20%. What is the cost price of the article?