d=vt (distance equals velocity times time)
v=d/t (velocity equals distance divided by time) In this case:
v=(22 1/2mi)/(1/3hr)
v=(45mi/2)/(3/hr)
v=(45*3)/2 mph
v=67.5 mph
We can easily check our answer since d=vt so:
d=(67.5mi/hr)(hr/3)=22.5 miles, so it was correct.