What is the probability of a man and a woman having a family of 5 children and all 5 being boys?

the probability is 1/32

Explanation:

The probability of producing a male (XY) is mostly determined by the male. the Y allele gives the characteristic male. While in the female, we have double X (XX). In reproduction the female contributes one of the alleles (X) and the male contributes either the X or the Y in each case.

        female     X           X

male

  X                   XX        XX

  Y                   XY        XY

XX= 1/2   XY = 1/2

So that we can have 1/2 chance of producing a female and 1/2 chance of producing a male. Thus, the the probability of having a male in each occurrence is 1/2. Since this occurred 5 times, so we have 1/2 x 1/2 x 1/2 x 1/2 x 1/2 = 1/32.