Answer: There are 160 miles he would drive before he needed to fill up.
Explanation:
Since we have given that
Number of miles Mr. Markle planned a trip = 360 miles
According to question, he calculated that he would have to fill up
into the trip.
So, Part of miles he would drive before he needed to fill up is given by

so, Number of miles that he would drive before he needed to fill up is given by

Hence, there are 160 miles he would drive before he needed to fill up.