Question: If a parent has genotype Aa, he transmits either A or a to an offspring (each with a 1/2 chance). The gene he transmits to one offspring is independent of the one he transmits to another. Consider a parent with three children and the following events: A = {children 1 and 2 have the same gene}, B = {children 1 and 3 have the same gene}, C = {children 2 and 3 have the same gene}. Show that these events are pairwise independent but not mutually independent.