Their car gets 30 miles per gallon in gas mileage. They are traveling for seven hours at a rate of 55 miles per hour. Assuming no stops, how much gas will they need to complete their seven hour trip?

distance = 7(55) miles = 385 miles

number of gallons of gas = 385/30 = appr 12.8 or 13 gallons

To calculate how much gas they will need for the seven-hour trip, we need to determine the total distance they will be traveling.

The formula to calculate distance is: distance = rate × time.

Given that they are traveling at a rate of 55 miles per hour for seven hours, we can calculate the total distance as follows:

distance = 55 miles/hour × 7 hours
distance = 385 miles

Now that we know the total distance of the trip is 385 miles, we can calculate how much gas they will need based on their car's gas mileage of 30 miles per gallon.

To calculate how many gallons of gas they will need, we divide the total distance by the car's gas mileage:

gas needed = distance / gas mileage
gas needed = 385 miles / 30 miles per gallon

Dividing 385 miles by 30 miles per gallon gives us:

gas needed = 12.83 gallons

Therefore, they will need approximately 12.83 gallons of gas to complete their seven-hour trip assuming no stops.