ANSWER
[tex]363.6 \: miles[/tex]
EXPLANATION
We were told that the motorist travelled 250 miles on 11 gallons of gas. This implies that,
[tex]250 \: miles \equiv11 \: gallons[/tex]
Now we want to find how far he could go on 16 gallons.
[tex]x \: miles \equiv16 \: gallons[/tex]
All other things being equal, the motorist should cover more than 250 miles with 16 gallons of gas.
Recall that: If more, less divides.
This implies that,
[tex]x = \frac{250 \times 16}{11} [/tex]
[tex]x = \frac{4000}{11} = 363.6 \: miles[/tex]
Therefore the correct answer is C.