SOLUTION: A class has 10 boys and 12 girls. Find the probabliltity of selecting a committee of four with at most two girls? I have the answer, which is 4620/ 7315. I got 7315 by doing 22C4.

Algebra ->  Permutations -> SOLUTION: A class has 10 boys and 12 girls. Find the probabliltity of selecting a committee of four with at most two girls? I have the answer, which is 4620/ 7315. I got 7315 by doing 22C4.      Log On


   

Question 615815: A class has 10 boys and 12 girls. Find the probabliltity of selecting a committee of four with at most two girls? I have the answer, which is 4620/ 7315. I got 7315 by doing 22C4. How do i get 4620?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
"at most two" means none, one, or two

none means all boys ___ 10C4

one ___ 12C1 * 10C3

two ___ 12C2 * 10C2

add the three cases to get 4620