conversations.from: human
conversations.value: Coby went on a road trip. He is traveling from Washington to Nevada but he needs to stop in Idaho which is 640 miles away from Washington and 550 miles away from Nevada to pick up some friends.  If Coby is traveling at a speed of 80 miles per hour going to Idaho and at a speed of 50 miles per hour from Idaho to Nevada, how many hours did it take for him to arrive at the destination?
  Solve it.
conversations.from: assistant
conversations.value: The estimated time of arrival from Washington to Idaho is 640/80= 8 hours.
  So, the estimated time of arrival from Idaho to Nevada is 550/50=11 hours.
  Therefore, It took him 11+8= 19 hours to arrive at the destination.