Train Travel A train leaves Barstow traveling east at 35kmh

Train Travel. A train leaves Barstow traveling east at 35km/h. One hour later, a faster train leaves Barstow, also traveling east on a parallel track at 40km/h. How far from Barstow will the faster train catch up with the slower one?

Solution

The 1st train is 35 km away when the 2nd train leaves.
The 2nd train gains on the slower train at 5 kph.
35/5 = 7 hours to overtake it.
In 7 hours the 2nd train will be 40*7 = 280 km from Barstow.
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As a check, the slower train will be 35*8 = 280 km from Barstow also.