We want to find ordered pairs \((a,b)\) where \(a\) can be either \(1\) or \(2\) and \(b\) can be either 3, 4, or 5. \(A \times B\) is the set of all of these pairs:
\begin{equation*}
A \times B = \{(1,3), (1,4), (1,5), (2,3), (2,4), (2,5)\}\text{.}
\end{equation*}