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A couple has two children. Find the probability that:(a) Both children are girls.(b) At least one child is a girl.(c) Both children are the same gender.

User Sunday
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1 Answer

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The probability that one child is a girl is 1/2, then the probability for both children to be girls is 1/2*1/2 = 1/4

(a) Answer: 1/4

The probability that at least one child is a girl is 1-P(b) where P(b) is the probability that both children are boys. P(b)=1/2*1/2=1/4

(b) Answer: 3/4

The probability that both children are the same gender is the sum of the probability of both being girls (1/4) plus the probability of both being boys (1/4).

(c) Answer: 1/2

User JamesD
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