What is the unit rate for 501.9 mi on 21 hours

To find the unit rate I recommend using this proportion.
509.1mi/1h   21h/x
Or just divide 509.1mi by 21h. The answer would be 24.242857, if you round it to the nearest hundredth it becomes 24.24. Therefore, the answer is 24.24 miles on 1 hour.
Hope this helps, please mark brainliest!

The unit rate for this problem would be finding how many miles per hour.

We can simply do this by doing this:

Number of miles
   = Number of miles per hour
Number of hours 

Number of miles: 501.9
Number of hours: 21 hours

                                                 501.9 
 Number of miles per hour =     = 23.9 
                                                    21

The unit rate is 23.9 mi/hr (miles per hour)

Figure it out your self