Martin's family is driving to the beach for vacation. The total trip is 680 miles and Martin's father averages 60 miles per hour on the trip. The distance remaining d is represented by the function d=-60h+680, where h is the number of hours since the family began driving.

Determine the appropriate input values for this situation.

Only (negative rational, negative whole, positive whole or positive rational) numbers make sense for the input because you cannot drive (negative or positive) hours. It does make sene to use (fractional or negative) numbers because you can drive for part of an hour.