In a class of 12 boys and 8 girls, a committee of three should be formed. What is the probability that there are at least two girls on the committee?
The total possible committees = C(20,3)
The probability is P(2 girls) + P(3 girls) =
[ C(8,2)* C(12,1) + C(8,3)] / C(20,3) =
[336 + 56 ] / 1140 =
392 / 1140 = 98/285 ≈ .349 ≈ 34.9%
