The sum of first 45 natural numbers is:

What are the two natural numbers whose product is 2400 and the sum of whose squares is 5200?

Find the sum of all three-digit numbers divisible by 9.

Which one of the following cannot be the square of a natural number?

Let m and n be natural numbers. What is the minimum value of (m + n) such that 33m + 22n is divisible by 121?

The number π − 22/7 is