At 6:00 A.M., a train leaves a station and travels at a rate of 45 mph. At 7:00 A.M., a second train leaves the same station on the same track and travels in the direction of the first train at a speed of 60 mph. At 9:00 A.M., how many miles separate the two trains?

Question

Quizplus · Accepted Answer

The first train travels for 3 hours (6:00 A.M. to 9:00 A.M.) at 45 mph, covering a distance of 135 miles. 
The second train travels for 2 hours (7:00 A.M. to 9:00 A.M.) at 60 mph, covering a distance of 120 miles (since it started an hour later). 
The distance between the two trains is simply the difference between the distances they covered, which is 135 - 120 = 15 miles. Therefore, the correct answer is (D) 15 mi.

At 6:00 AM