Boys and girls

There are 11 boys and 18 girls in the classroom. Three pupils will answer. What is the probability that two boys will be among them?

Correct result:

p =  27.0936 %

Solution:

n=11+18=29  C2(3)=(32)=3!2!(3−2)!=31=3  p=100⋅ (32)⋅ 11n⋅ 10n−1⋅ 18n−2=100⋅ 3⋅ 1129⋅ 1029−1⋅ 1829−2=5500203=27.0936%

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Showing 1 comment:
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Math student
Answer is not accurate.correct answer is .2679076632908277

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