Answer
$t\leq 4 $ or $ t \geq 18$.
The graph is shown below.
Work Step by Step
$t$ is less than or equal to $4$.
$\Rightarrow t\leq 4$
or
$t$ is no less than $18$.
$\Rightarrow t\geq 18$
The compound inequality is
$t\leq 4 $ or $ t \geq 18$
Graph the union of the graphs of $t\leq 4 $ or $ t \geq 18$.
