change to improper fractions
42 1/3
(3* 42 +1) /3 = 127/3
1 1/3 = (3*1 +1) /3 = 4/3
127/3 divided by 4/3
copy dot flip
127/3 * 3/4
127/4
31 3/4 miles per hour
He drove 31 3/4 miles in one hour
31 3/4 miles 1 mile
------------ = ------------
1 hours x hour
using cross products
31 3/4 * x =1*1
x = 1/ 127/4 (copy dot flip)
x = 1 * 4/127
x = 4/127
it takes 4/127 of 1 hour (approx .03 hours)
