A bookseller bought 500 text books for 20,000. He wanted to sell them at a profit so that he get 50 books free. At what profit percent should he sell them?
If by increasing the price of a ticket in the ratio 8:11 the number of tickets sold fall in the ratio 23:21 then what is the increase (in Rs) in revenue if revenue before increase in price of ticket was Rs 36,800?