Question

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?

A table showing Rate in mile per hour, Time in hours, and Distance in miles. The first row shows First Car and has 60, t, and 60 t. The second row shows Second Car and has, 55, t, and 55 t.

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

Answer 1

60t + 55t = 150

Reason: their distances add to 150 miles, so (60 miles/hour)(t) + (55 miles/hour)(t) = 150. (Solve: 115t = 150, t = 150/115 = 30/23 ≈ 1.304 hours.)