Kalvin's sister Kate finds yet another way for him to pick his
breakfast. She places one blue marble and one red marble in each
of two bags. She says that each morning he can choose one marble
from each bag. If the marbles are the same color, he eats Cocoa Blast.
If not, he eats Health Nut Flakes. Explain how selecting one marble
from each of the two bags and tossing two coins are similar.