Students are traveling in two cars to a football game 135 miles away. The first car leaves on time at an average speed of 45 mph. The second car starts 30 minutes later at an average speed of 55 mph. How long will it take for the second car to catch up to the first car? Will the second car catch the first car before it arrives at the game?
Let it take x hrs for second car to catch up ( x hrs after the first car left)
This shows how to determine the intersection time between two cars.