Use the formula for distance, speed and time:
distance = speed \u00D7 time
d=s \u00D7 t
Solve for s:
Note: Since the wording in the question lists the time traveled as "approximately 5 hours", we use the word "about" in all of the answer choices. The question, however, asks for the "miles per hour," not the "approximate" miles per hour, so none of the other answers would be correct.