From a group of 3 boys and 3 girls, 4 children are to be randomly selected. What is the probability that equal numbers of boys and girls will be selected?
~$$\frac{1}{10}~
~$\frac{4}{9}$~
~$\frac{1}{2}$~
~$\frac{3}{5}$~
~$\frac{2}{3}$~
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C(2,3)*C(2,3)/C(4,6)
C(2,3)*C(2,3)/C(4,6)
Nice,你这个方法更简洁,谢谢~~
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