Final answer:
To mount four wheels on 50 vehicles, 1000 lug nuts are needed.
Step-by-step explanation:
To mount one wheel, five lug nuts are needed. Therefore, to mount four wheels, we can calculate the total number of lug nuts needed by multiplying the number of wheels by the number of lug nuts needed for each wheel.
4 wheels x 5 lug nuts = 20 lug nuts.
Now, we need to calculate the total number of lug nuts needed to mount four wheels on 50 vehicles.
20 lug nuts x 50 vehicles = 1000 lug nuts.
Therefore, 1000 lug nuts are needed to mount four wheels on 50 vehicles.