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Abe holds 1 green and 1 red jelly bean in his hand. Bob holds 1 green, 1 yellow, and 2 red jelly beans in his hand. Each randomly picks a jelly bean to show the other. What is the probability that the colors match? (2013 AMC 8 Problem, Question \#14) 
Overseas Competition->Knowledge Point->Counting Modules->Statistics and Probability
The probability that both show a green bean is $\frac{1}{2} \cdot \frac{1}{4}=\frac{1}{8}$. The probability that both show a red bean is $\frac{1}{2} \cdot \frac{2}{4}=\frac{1}{4}$. Therefore the probability is $\frac{1}{4}+\frac{1}{8}=\left(\right.$ C) $\frac{3}{8}$ 