Sujoy Kumar Datta

The sum of all 4 digit even natural numbers of the form "aabb", where a>0, is

The number of positive integers n in the range 1 < n < 40 such that the product (n–1)(n–2)...3.2.1 is not divisible by n is

The number of factors of the square of a natural number is 135. What is the maximum possible number of factors of the cube of the same number?

In a three-digit number, the unit digit is twice the tens digit and the tens digit is twice the hundreds digit. The same number is written as 3XY in base 8. What is the sum of X and Y in the decimal system.

Which of the given values of A allow the expression to result in a prime number?