Question 515559
d = r*t is the basic distance equation
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Train A
d = 60mph * t hr
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Train B
d = 80mph * (t-1/4) hr  : train B is 1/4 hr behind Train A
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When Train B catches up to Train A, they will have traveled the same distance.
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60t = 80(t - 1/4)
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60t = 80t - 20
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-20t = -20
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t = 1 hr
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So, in 1 hr Train A will have traveled 60 miles.
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Train B will have traveled for 3/4 hr at 80 mph, which is 60 miles.
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Re-read the question to determine what the required answer is.
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Answer:  Train B will overtake Train A at 12:20 a.m.
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Done.