In a college 12% of all the students are interested in sports, 10% of the total students are interested in singing and three-fourth of the total students are interested in dancing and remaining 15 students are not interested in any activity, How many total students are there in the college?

Joseph's income is decreased by 10%, by what percent the new income has to be increased to bring his income back to the previous level?

The rate of work of A and B is in the ratio 2 : 3. What will be the ratio of the days taken by them to complete the work?

The number obtained by subtracting two-third of 75% of 600 from a number is 320, what is the original number?

If the price of petrol is reduced by 10%, by how much should a consumer increase the consumption of petrol so that his expenditure on petrol does not decrease?

'The total surface area of a cube is 600 sq cm, what will be the length of its diagonal?

A shopkeeper charges his customers 15% above the cost price, if a customer has bought a sofa-set for 9039, then for how much did the shopkeeper buy it?

The volume of a cuboid is 2 times the volume of a cube. If the dimensions of the side are 9 cm by 8 cm and 6 cm, then the total surface area of the cube is