conversations.from: human
conversations.value: Solve the following math problem: John drives 1000 miles a month.  He needs to get an oil change every 3000 miles.  He gets 1 free oil change a year.  If an oil change costs $50, how much does he pay a year?
conversations.from: assistant
conversations.value: He needs to get an oil change every 3000/1000 = 3 months
  So he gets 12/3 = 4 oil changes a year
  That means he pays for 4-1 = 3 oil changes a year
  So he pays 3*$50 = $150 a year