By "completely" we mean a son which has both his grandfather's eyes and his hair. Based on this fact, can you now guess Bob's hair colour and genotype? How can Bob be absolutely sure that he can't have an auburn son?
On the other hand, Alice has hopes having a daughter not looking like herself, but like her mother. But since Alice is brown - eyed, what does this mean about her mother? What can we conclude about the genotype of Alice?