Question 261148
Let both meet t hours after 9am.
Distance travelled by Jessica in t hours = 4.5t
Distance travelled by Lauren in t hours  = 3.75t
The difference is 4.5t-3.75t = 1 mile
                  0.75t = 1
                  t = 1/0.75 hours
                  t = 1 1/3 hours
                  t = 1h 20m