A die is thrown. $A$ is 'a multiple of 2' and $B$ is 'a multiple of 3'. How many outcomes are in $A \cup B$?

Explanation

1. 01

   $A = \{2, 4, 6\}$ and $B = \{3, 6\}$.

2. 02

   $A \cup B = \{2, 3, 4, 6\}$: 4 outcomes, with 6 counted once.