In a school 80% of the students are girls. The number of boys are 500. Then the total number of students in the school is

A number is decreased by 20% to get another number. The number so obtained is increased by 200% to get a third number. The difference of the third number and the original number is what percentage more or less than the difference of second and the third number?

Two numbers are 90 % and 75 % lesser than a third number. By what % should the first number be increased so that it becomes equal to the second number? 

If there is a 25 percent reduction in the price of rice, a person can buy 10 kg more rice for Rs 600. The reduced price per kg of rice is.

Mohan gets 4 marks for each correct sum and losses 1 marks for each wrong sum. He attempted 30 sum and obtains 50 marks. The number of sums solved correctly is? 

If the cost price of 15 tables is equal to the selling price of 20 tables. The loss percent is:

A dozen pairs of socks quoted at 180 are available at a discount of 20 %. How many pairs of socks can be bought for 48? 

A book seller allowed 10 % discount on printed price. He gets 30 % commission from publisher. His profit in percent will be?