conversations.from: human
conversations.value: Barry stands on his head for 10 minutes at a time, but then he must sit for 5 minutes before he can take another turn standing on his head.  How many turns can Barry take standing on his head during a single 2-hour period?
conversations.from: assistant
conversations.value: Each turn Barry takes standing on his head lasts for 10+5=15 minutes.
  2 hours is 60*2=120 minutes.
  Barry can take 120/15=8 turns standing on his head over two hours.