i'll convert these fractions into decimals because it'll be easier to solve that way.
[tex]21\frac{1}{2} =21.5[/tex]
[tex]2/3 = 0.66[/tex] (nearest 2dp)
[tex]s = \frac{d}{t}[/tex]
[tex]s = \frac{21.5}{0.66}[/tex]
[tex]s=32.57[/tex]
33 miles per hour (rounded to the nearest whole number)