Quantitative Aptitude - Arithmetic Ability Questions

The difference between Charles' and Shriya's ages is 6 years. When they married each other 30 years ago, 4 times Charle's age was the same as 5 times the age of Shriya. What is the current sum of their ages?

The average age of a batch of 19 members is 24 years. If the age of the faculty be included, then the average increases by 4 months. What is the age of the faculty?

By what least number should 1200 be multiplied so that it becomes a perfect square?

What is the difference (in Rs) between compound interest (compounded annually) and simple interest for 3 years on a principal of Rs 4000 at the rate of 30% per annum?

If X + 2Y = 27 and X - 2Y = -1, find the value of Y.

What is the square root of 9409?

What is the square root of 5041?

If the standard deviation of a population is 7, what would be the population variance?