.
Let d be the distance under the question.
"A" family spent
hours for their trip.
"B" family spent
hours for their trip.
Difference in time was 2 hours, according to the condition.
Hence, from the condition, you have this "time" equation
-
= 2 hours.
To solve it, multiply both sides by 200. You will get
5d - 4d = 2*200
d = 400.
It is your ANSWER : the distance is 400 miles.
Solved.