May I ask what’s this answer?
I wasn’t in class today:(

Answer:
[tex]\left[\begin{array}{ccc}5&15&20\\120&360&480\end{array}\right][/tex]
Explanation:
For every 5 gallons, there's 120 miles. If we know we have 360 miles, we can see how many times 120 goes into 360, which is 3.
5 * 3 = 15.
Then just reverse the process