[tex] \frac{20 meters}{1 second} \frac{60 seconds}{1 minute} \frac{60 minutes}{1 hour} [/tex]
the fractions are set up so that each unit cancels out until its only meters/hour
you can multiply all the numerators together to get 72000 and all the denominators to get 1
72000 meters/1 hour
72000 meters in 1 hour
hope this helped
