SOLUTION: In a group of 30 pupils, 20 are girls and 10 are boys. From these 30 pupils, 5 are chosen at random. In how many ways may they be chosen? And find the probability that there are ex

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Question 271215: In a group of 30 pupils, 20 are girls and 10 are boys. From these 30 pupils, 5 are chosen at random. In how many ways may they be chosen? And find the probability that there are exactly 3 girls in the group of 5 chosen.
Answer by stanbon(75887) About Me  (Show Source):
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In a group of 30 pupils, 20 are girls and 10 are boys. From these 30 pupils, 5 are chosen at random. In how many ways may they be chosen?
Ans: 30C5 = 142506
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And find the probability that there are exactly 3 girls in the group of 5 chosen.
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Ans: [20C3*10C2]/30C5 = 513000.36/142506 = 0.36
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Cheers,
Stan H.