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A box contains five cards, numbered $1,2,3,4$, and $5$. Three cards are selected randomly without replacement from the box. What is the probability that $4$ is the largest value selected? (2017 AMC 8 Problems, Question \#10) 
Overseas Competition->Knowledge Point->Calculation Modules
There are $\_5C\_3 = 10$ possible groups of cards that can be selected. If $4$ is the largest card selected, then the other two cards must be either $1$,$2$, or $3$, for a total $\_3C\_2 = 3$ groups of cards. Then, the probability is just $(\text{C}) \frac{3}{10}$. 