Answer: 48 minutes
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Step-by-step explanation:
distance = rate*time
Train A travels a distance of 100x kilometers after x hours elapse
Train B travels 150x kilometers
The two trains pass each other when their distances add up to the 200 kilometers mentioned. Assume the two trains are on separate parallel tracks.
trainA+trainB = 200
100x+150x = 200
250x = 200
x = 200/250
x = 4/5
They will pass each other at the 4/5 hour marker
This converts to (4/5)*60 = 0.8*60 = 48 minutes