A train leaves a station and travels at 50 miles per hour. Fifteen minutes later, a second train leaves the same station and travels in the same direction on parallel tracks at 60 miles per hour. How long it will be before the second train overtake first?

Let the first train be Train A and the second be Train B

In 15 minutes each has travelled:
Train A 50mph * 1/4 hour = 12.5 miles
Train B 0 miles

We let the time needed to take Train B overtake Train A be x (in hours)

12.5 miles + 50mph * x = 60 mph * x
12.5 + 50x = 60x
12.5 = 10x
1.25 = x

Therefore, after 1 hour and 15 minutes, the second train can overtake the first.

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Jeremiaid Jeremiaid · Answer 2

Rate (Time) = Distance
Train A: 50 x + 1/4 = 50x + 50/4
Train B: 60 x = 60x
If Train B overtakes Train A, then at that time, they have equal distances.
50x + 12.5 = 60x
12.5 = 10x
1.25 = x
Answer: 1 hour and 15 minutes