<human>:  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?
<bot>: How far is the destination? ** The distance to the destination is 4 hours * 50 miles/hour = <<4*50=200>>200 miles.
How long would it take if it traveled at 100 miles per hour? ** Traveling at 100 miles per hour, it will take 200 miles / (100 miles/hour) = <<200/(100)=2>>2 hours.
#### 2