Algebra-1

A unit rate is a ratio where the second quantity (the denominator) is 1. It represents how much of one quantity corresponds to a single unit of the other.

70 miles per hour a unit rate because it compares 70 miles to 1 hour, which is a direct comparison to 1 unit of time.

For option A, 70 miles per 1.5 hours

This is not a unit rate because the time is not 1 hour but 1.5 hours. To turn this into a unit rate, you would divide 70 miles by 1.5 hours.