Speed of Luke while driving=50 miles per hour
Speed of Aisha while driving=55 miles per hour
⇒After x hours
Distance =Speed × Time
Distance travelled by luke after x hours =50x mile
Distance travelled by Aisha after x hours =55x mile
We will find common multiple of 50 and 55 which is 550.
So, After 11 hours luke will cover 550 miles and after 10 hours Aisha will cover 550 miles.
So, Aisha will be always ahead of Luke if their speeds are 55 miles per hour and 50 miles per hour respectively on the highway.
So, 55x>50x.