Two cards are drawn one after the other, without replacement, from a pack of 52, and $X$ is the number of aces drawn. What is $P(X = 1)$?

Explanation

1. 01

   One ace can come first or second: $\frac{4}{52} \times \frac{48}{51}$ for ace then not, and $\frac{48}{52} \times \frac{4}{51}$ for not then ace.

2. 02

   $P(X = 1) = 2 \times \frac{4 \times 48}{52 \times 51} = \frac{32}{221}$.