conversations.from: human
conversations.value: Grayson has 100 questions on a test. He answers some of the questions for 2 hours, taking two minutes for each answer, then realizes he doesn't know the rest of the questions. How many questions does Grayson leave unanswered when he submits his test?
conversations.from: assistant
conversations.value: Each hour contains 60 minutes, so after 2 hours he took 2*60 = 120 minutes.
  If each question takes two minutes, then he answered 120/2 = 60 questions.
  Unanswered questions is 100-60 = 40 questions