To calculate the gas needed, we can use the following formula:
Gas needed (in gallons) = Distance (in miles) / Fuel efficiency (in mpg)
Plugging in the values, we get:
Gas needed = 852 miles / 25 mpg
= 34.08 gallons
Therefore, you would need approximately 34 gallons of gas to travel 852 miles with a vehicle that has a fuel efficiency of 25 mpg.
It's important to note that the actual gas consumption may vary depending on various factors such as traffic, road conditions, vehicle load, and driving style.