Two cars that are 150 miles apart start driving toward each other on parallel roads. The average speed of the first car is 60 miles per hour. The average speed of the second car is 55 miles per hour. Which equation can be used to determine t, the time it takes for the two cars to pass each other?

60t – 55t = 0
60t + 55t = 1
60t + 55t = 150
60t – 55t = 150