Question 1039889
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Boys and girls. Alice and Bill are planning to have three children. (Assume it is equally likely for a boy or a girl to be born.)  

What is the probability that not all three will be of the same gender?
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P(all 3 are girls) = {{{1/8}}}.


P(all 3 are boys) = {{{1/8}}}.


P(all 3 are of the same gender) = {{{1/8 + 1/8}}} = {{{1/4}}}.


The probability that not all three will be of the same gender is {{{1-(1/4)}}} = {{{3/4}}} = 0.75.