Find the average of natural numbers from 1 to 65?

 What will be value of (74.6-38.9-5.7)/(26.4-18.9) ? 

a:b = 3:7 and b:c = 9:5. What is a:b:c? 

If y exceeds x by 25%, then x is less than y by what percentage?

  If A:B = 2:3, B:C = 4:5 and C:D = 6:7, then A:B:C:D is
 

If sin A + cos A = x, then the value of (x+1)(x-1) is:

A student scored 75% of the total marks. The total number of marks were 400. How many marks did the student score?

An urn contains 6 orange, 5 yellow and 2 grey marbles. If 2 marbles are picked at random, what is the probability that both are orange? 

The monthly incomes of Raja, his wife, and their son are Rs. 7,000, Rs. 3,000, and Rs. 5,000 respectively. Find their average income.

The population of a town increases by 4% annually but decreases by 0.5% annually due to emigration. What will be the increase percentage in three years?