Question

In a family of 10 children, where both parents are heterozygous for albinism, what mathematical equation predicts the probability that 8 are normal and 2 are albino?

Answer 1

In a cross between two heterozygous parents, the probability that a child is homozygous for albinism is 1/4. So out of 10 children, the probability that 8 are normal and 2 are albino is

$\dbinom{10}2\left(\dfrac14\right)^2\left(1-\dfrac14\right)^{10-2}\approx0.2816$