If a vehicle travels 660 miles in 6 hours, what is its average speed?

To determine the average speed of a vehicle, one can apply the formula:

[

\text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}}.

]

In this case, the vehicle travels a total distance of 660 miles over a total time of 6 hours. Plugging these values into the formula yields:

[

\text{Average Speed} = \frac{660 \text{ miles}}{6 \text{ hours}} = 110 \text{ miles per hour}.

]

So, the average speed of the vehicle is 110 miles per hour, which aligns with the correct choice. This figure represents a straightforward calculation that shows how distance and time are directly related when calculating speed.

The other options either do not match this computed average or are derived from inaccuracies in calculating distance, time, or both. Thus, the correct answer reflects a consistent understanding of the average speed formula.