SOLUTION: An organization consisting of 22 women and 16 men needs to select from its ranks a committee of 4 people. If the members of the committee are selected at random, what is the pro

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Question 1153809: An organization consisting of 22 women and 16 men needs to select from its ranks a committee of 4 people.
If the members of the committee are selected at random, what is the probability that the committee will have exactly 2 men?

Found 3 solutions by ikleyn, AnlytcPhil, Edwin McCravy:
Answer by ikleyn(52798) About Me  (Show Source):
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.

P = %28C%5B22%5D%5E2%2AC%5B16%5D%5E2%29%2FC%5B22%2B16%5D%5E4


C%5B22%5D%5E2 = %2822%2A21%29%2F2 = 231;

C%5B16%5D%5E2 = %2816%2A15%29%2F2 = 120;

C%5B38%5D%5E4 = %2838%2A37%2A36%2A35%29%2F%281%2A2%2A3%2A4%29 = 73815;


    P = %28231%2A120%29%2F73815 = 0.3755.      ANSWER
ANSWER

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I agree with critics by Edwin.

I just took off that part of my solution, which was incorrect.

I also expanded the first part of my solution, placing calculations explicitly, and got the same answer for the probability,
as Edwin got.

So now you see the corrected version in my post.


Thanks to Edwin for his note (!)



Answer by AnlytcPhil(1806) About Me  (Show Source):
You can put this solution on YOUR website!
Ikleyn first answer is correct, but her second way is incorrect for it
calculates the probability of choosing them in this order:
1. any woman first from the 22 women, 
2. any woman second from the remaining 21 women,
3. any man third from the 16 men,
4. any man fourth from the remaining 15 men.

But the order in which they are chosen does not matter.

4 people with exactly 2 men also have exactly 2 women.

Choose the 2 men any of "16 CHOOSE 2" or 16C2 = 120 ways
For each of those 120 ways to choose the 2 men, there are 
"22 CHOOSE 2" or 231 ways to choose the 2 women. That
amounts to (120)(231) or 27720 ways.

The number of ways to choose ANY 4 from the 22+16=38 people is
"38 CHOOSE 4" or 38C4 = 73815 ways.

So the probability of choosing 4 with exactly 2 men is
27720 ways out of 73815 or

27720%2F73815

which reduces to

264%2F703

and which is approximately 37.6% of the time 2 men and 2 women
will be chosen.

Edwin

Answer by Edwin McCravy(20059) About Me  (Show Source):
You can put this solution on YOUR website!
FYI, Edwin and AnlytcPhil are the same person. J