A freight train and a passenger train leave a rail yard at the same time and travel on parallel tracks. The passenger train travels 6 mph faster than the freight train. The combined distance traveled after 2 hours is 100 miles. What is the average speed of each train?
A) 22 mph; 28 mph
B) 24 mph; 30 mph
C) 21 mph; 27 mph
D) 19 mph; 25 mph

Question

Quizplus · Accepted Answer

The passenger train travels 6 mph faster than the freight train, so the speed of the passenger train is x + 6 and the speed of the freight train is x. The combined distance traveled after 2 hours is 100 miles, so the total distance traveled by the passenger train is (x + 6) * 2 = 2x + 12 miles and the total distance traveled by the freight train is x * 2 = 2x miles. The combined distance traveled is 100 miles, so 2x + 12 + 2x = 100. Solving for x, we get x = 44. Therefore, the speed of the passenger train is 44 + 6 = 50 mph and the speed of the freight train is 44 mph. The average speed of each train is 50 mph / 2 = 25 mph and 44 mph / 2 = 22 mph.

A Freight Train and a Passenger Train Leave a Rail