Showing what's behind the curtain

Find the number of factors in an enormous factorial.

The prime factorisation of binomial coefficients

Find the number of trailing zeros in a factorial

Investigate the game of chance involving colored discs.

Find the sum of the digits in 100!

Find the number of routes from the top left corner to the bottom right corner in a rectangular grid.

Count the values of C(n,r), for 1 ≤ n ≤ 100, that exceed one-million.

Determine the number of factorial chains that contain exactly sixty non-repeating terms.

Find the sum of all numbers which are equal to the sum of the factorial of their digits.