Final answer:
The question requires comparing the fuel economy of Genesis's and Lavaughn's cars in miles per gallon to determine how many miles less one car travels per gallon than the other; however, the question cannot be answered without the specific fuel economy figures for both vehicles.
Step-by-step explanation:
To determine how many miles less Genesis's car travels on one gallon of gas than Lavaughn's car, we need to compare the fuel economies of the two vehicles in miles per gallon. This information, however, is not provided explicitly in the question, thus the question cannot be answered as it is. We need the fuel economy figures for both Genesis's car and Lavaughn's car to make the comparison.
For example, if Genesis's car averages 30 miles per gallon and Lavaughn's car averages 35 miles per gallon, then Genesis's car travels 5 miles less per gallon than Lavaughn's car. The correct approach involves using the known distances and amounts of gas used to calculate the fuel economy of each vehicle and then comparing them.