Answer
There are approximately 24.6 hours in a Martian day.
Work Step by Step
Mars rotates at a rate of 0.2552 radians per hour. We can find the number of hours $N$ in a Martian day:
$N = \frac{2\pi~rad/day}{0.2552~rad/hr}$
$N = 24.6~hr/day$
There are approximately 24.6 hours in a Martian day.
