SOLUTION: I've tried to figure this out, but I have not gotten very far. Here's the problem: If 4 balls are drawn simultaneously from an urn containing 7 red balls and 6 white balls, wha

Algebra ->  Probability-and-statistics -> SOLUTION: I've tried to figure this out, but I have not gotten very far. Here's the problem: If 4 balls are drawn simultaneously from an urn containing 7 red balls and 6 white balls, wha      Log On


   



Question 945318: I've tried to figure this out, but I have not gotten very far. Here's the problem:
If 4 balls are drawn simultaneously from an urn containing 7 red balls and 6 white balls, what is the probability that exactly 3 balls will be red?

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
There are 16 possible outcomes
RRRR
RRRW
RRWR
RRWW
RWRR
RWRW
RWWR
RWWW
WRRR
WRRW
WRWR
WRWW
WWRR
WWRW
WWWR
WWWW
Of those, 4 outcomes have exactly 3 red balls (RRRW,RRWR,RWRR,WRRR).
So,
P=4%2F16=1%2F4