Which letter-cluster will replace the question mark (?)

Which of the following numbers is divisible by 11?

If a nine-digit number 785x3678y is divisible by 72, then the value of (x − y) is:

Find the smallest number divisible by 12, 18, and 24 that is greater than 1000.

What is the value of a so that the seven-digit number 4645a52 is divisible by 72?

Determine the remainder when 44¹² is divided by 7?

Which of the following numbers will completely divide 4¹² + 4¹³+ 4¹⁴ + 4¹⁵ + 4¹⁶?

What is the minimum value of X for which 437X6 is divisible by 9?

What will be the remainder when 7⁴² is divided by 48?

How many divisors does the number 5040 have?