Step-by-step explanation:
Let the distance be represented below as

Let the time be represented below as

For a car moving at a constant speed, the distance traveled varies directly with the time spent driving.
This can be represented below as

Substitute d=400 and t=8 in the formula below

Replace the value of r in the formula below, we will have

how many miles does it travel in 6 hours?
This can be calculated by substituting the value of t=6 hours in the formula above

Hence,
The final answer is
