Problem:
I've been working a little with M. G. Bulmer's Principles of Statistics (Dover, 1979) and cannot see how to properly compute half of one question. This should be a basic probability computation, but I am not getting the same answer as the book's suggestion.
Question: If the three genotypes (i.e., AA, Aa, aa) are all distinguishable, find the probabilities that
a) a pair of siblings
b) a pair of unrelated individuals will appear the same when p=q=.5.
Please show all the calculations.