Question

In how many ways can Troy select nine marbles from a bag of twelve, identical except for color, where three are red, three blue, three white, and three green.

Answer 1

Combinations without repetition (n=12, r=9)

C (n,r)= n!/r!(n-r)!
=12!/9!(12-9)!
= 220
---> That was solved with a scientific calcuator.

220 entries. = Troy has 220 ways to select nine marbles from a bag of twelve.