A couple decides to have 4 children. If they succeed in having 4 children and each child is equally likely to be a boy or a girl, what is the probability that they will have exactly 2 girls and 2 boys?


~$3 \over 8$~

~$1 \over 4$~

~$3 \over 16$~

~$1 \over 8$~

~$1 \over 16$~

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