10 miles = 3 hours
10/3 miles = 1 hour (divide both sides by 3)
A unit rate always has "1" in the denominator. In terms of speed, unit rates will have 1 unit to correspond to the time value (in this case 1 hour).
So,
[tex]\frac{10 \text{ miles}}{3 \text{ hours}} = \frac{10/3 \text{ miles}}{1 \text{ hour}}[/tex]
Answer: Choice B
