Answer :
Let A be the total distance to your Aunt, who is 255 miles away.
Let B be the distance from getting off the interstate to your aunt.
Let C be the distance from your house to the interstate.
The question asks how many hours you will be traveling on the interstate.
There:
= A - B - C
= 255 - 10 - 14
= 231
If you drive 55 miles per hour, then you divide the distance on the interstate by speed you drive on the interstate :
= 231 ÷ 55
= 4.2 hours
Let B be the distance from getting off the interstate to your aunt.
Let C be the distance from your house to the interstate.
The question asks how many hours you will be traveling on the interstate.
There:
= A - B - C
= 255 - 10 - 14
= 231
If you drive 55 miles per hour, then you divide the distance on the interstate by speed you drive on the interstate :
= 231 ÷ 55
= 4.2 hours