If two numbers are respectively 20% and 50% of a third number, what is the percentage of the first number to the second?

A man purchases 100 copies of a book from the publisher and gets a discount of 25%. He buys 50 copies from a retailer at a discount of 10%. He got an overall discount of:

If on a marked price the difference of selling prices with a discount of 30% and two successive discounts of 20% and 10% is 72, then the marked price (in rupees) is  

A fan s listed at ₹ 150 with a discount of 20%. What additional discount must be offered to the customer to bring the net price to ₹ 108

A shopkeeper list the price of an article as ₹ 500. But he gives a certain discount which allows the buyer to pay ₹ 500 for the article including 10% sales tax. The rate of discount is 

Ramesh marks his goods 30% above cost price. If he sells the item for ₹ 910 after allowing of 15% discount. Find his cost price.

The marked price of an article is ₹ 100. A discount series of 5%, 10% successively reduces the price of an article by 

A dealer marks his goods at such a price that after allowing a discount of 12.5% for cash payment, he makes a profit of 20%. What is the marked price (in rupees) of the article which costs him Rs. 210?