Question 730820: A grab bag contains 10 $1 prizes, 6 $5 prizes, and 5 $20 prizes. Three prizes are chosen at random. Find the probability that exactly 2 $20 prizes are chosen? I get that I needed to figure 21C3=1330 (Total # of ways to choose 3 prizes), and that number will need to be divided into the number of ways you can pick so two are $20 prizes, but I can't figure out how to get the number of ways you can pick so two are $20 prizes? I can't get that numerator. Please help, I'm having this problem on all my homework, stuck in the same spot, and the homework help button skips over this part. Thanks!
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A grab bag contains 10 $1 prizes, 6 $5 prizes, and 5 $20 prizes. Three prizes are chosen at random. Find the probability that exactly 2 $20 prizes are chosen?
----
There are 21 prizes.
-------------------------------
# of ways to succeed: 5C2*11C1 = 10*11 = 110
# of possible outcomes: 21C3 = 1330
---
Probability of selecting 2 $20 prizes when choosing 3: 110/1330 = 11/133
----------------
Cheers,
Stan H.
|
|
|
