Gas Mileage = Distance (miles) / Fuel Used (gallons)
For Car A:
Gas Mileage = 125 miles / 5 gallons = 25 miles per gallon
For Car B:
Gas Mileage = 120 miles / 6 gallons = 20 miles per gallon
Comparing the two gas mileages, we can see that Car A has a better gas mileage of 25 miles per gallon compared to Car B's 20 miles per gallon. This means that Car A is more fuel-efficient and travels more miles per gallon of fuel than Car B.