Answer
$4.91\ h$
Work Step by Step
Since the speed and time of travel vary inversely when driving a given distance, then we can set up an inverse relationship as:
(speed)( time)=(speed)( time).
Now, we have
$$
45\times6=55\times x\Longrightarrow x=\frac{45\times6}{ 55}=4.91 \ h
.$$
