Answer:
Yes, the estimate given is reasonable.
Step-by-step explanation:
If we do the maths of this question with estimates, we can guess that the average mileage be about 26 or nearly 25 for easy calculation.
If each friend drives between 57 and 63, then the average be about 60.
So for a person with a mileage of 25 to go nearly 60 miles, he would have to use nearly 2.5 gallons. Therefore, for the 3 friends, it would be 2.5*3 = 7.5 nearly 7 gallons.
Thus his estimation was reasonable.