conversations.from: human
conversations.value: A train takes 4 hours to reach a destination at a speed of 50 miles per hour. How long would it take if it traveled at 100 miles per hour instead?
  Give me a clear explanation.
conversations.from: assistant
conversations.value: The distance to the destination is 4 hours * 50 miles/hour = 200 miles.
  Traveling at 100 miles per hour, it will take 200 miles / (100 miles/hour) = 2 hours.