ANSWER
4 miles
EXPLANATION
Henry's drive is 12 miles long and he has finished 1/3 of the drive so far.
This means that to find how far he has driven, we have to find 1/3 of 12 miles.
That is:
[tex]\frac{1}{3}\cdot\text{ 12 = 4 miles}[/tex]That is the answer.
