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

Aman's expenses are 30% more than Vimal's expenses and Vimal's expenses are 10% less than Raman's expenses. If the sum of the expenditure of all three is Rs. 6,447, then what is the Expenditure of Aman?

If $$ {66{2\over 3}}{ \%}$$ of 75 % of one-eighth of a certain number is 179, then $$ {33{1\over 3}}{ \%}$$ of three – fourth of that number is:

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.

If X is 20% less than Y, then find the value of $${Y-X\over Y}$$ and $${X\over X-Y }$$

Madhur scored 101 marks in Hindi, 100 in Science, 96 in Sanskrit, 108 in Maths and 78 in English if the maximum marks in each subject is equal and Madhur secured 84 percent marks in all the subjects. What will be the maximum marks for each subject?

If the diameter of a wire is decreased by 10% by how much per cent (approximately) will the length be increased to keep the volume constant?