To determine how far the truck could drive with 8 gallons of gasoline, we first need to find the truck's fuel efficiency in miles per gallon.
The truck drives 200 miles using 4 gallons of gasoline.
Fuel efficiency can be calculated as follows:
\[ \text{Miles per gallon} = \frac{\text{Total miles driven}}{\text{Total gallons used}} = \frac{200 \text{ miles}}{4 \text{ gallons}} = 50 \text{ miles per gallon} \]
Now that we know the truck's fuel efficiency is 50 miles per gallon, we can calculate how far the truck can drive with 8 gallons:
\[ \text{Distance with 8 gallons} = \text{Miles per gallon} \times \text{Total gallons} = 50 \text{ miles per gallon} \times 8 \text{ gallons} = 400 \text{ miles} \]
Thus, the truck could drive 400 miles with 8 gallons of gasoline.