19.8 miles per gallon
Explanation:We would be taking the unit of the odometer to be in miles since it was not stated.
We need to find the difference in the odometer as this will give us the distance covered between them
Distance = 25,214.7 miles - 24,848.4 miles
Distance = 366.3 miles
To find the miles per gallons, we would divide the distance by the number of gallons to fill the tank
number of gallons = 18.5 gal
= 366.3 miles/ 18.5 gal = 19.8 miles per gallon
The van got 19.8 miles per gallon