Question

A couple plans to have 4 children. Assuming that boys and girls are equally likely, find the probability that the couple will have at least one boy?

Answer 1

$A$ - the couple will have at least one boy

$A'$ - the couple will have only girls

$P(A)=1-P(A')$

$|\Omega|=2^4=16\\|A'|=1\\\\P(A')=\dfrac{1}{16}\\\\P(A)=1-\dfrac{1}{16}=\dfrac{15}{16}$