Then, using the formula Distance = Fuel Efficiency * Liters of Gas, we can calculate the liters of gas used:
Liters of Gas = Distance / Fuel Efficiency
Liters of Gas = 1500 km / 7 km/L
Liters of Gas = 214.29 L
Therefore, you would use approximately 214.29 liters of gas on a 1500 km trip with a vehicle that gets 7 km/L.