Question 573800
this is the notation for the number of COMBINATIONS (order not important) of 2 things from a group of 8 things


nCr = n! / [r! * (n - r)!]


! is the notation for factorial ___ it means the product of the number and all the numbers down to one
___ 5! = 5 * 4 * 3 * 2 * 1