conversations.from: human
conversations.value: Solve the math problem: John decided to sell his PlayStation to buy a new computer.  The computer's cost was $700 and the accessories cost was $200.  The PlayStation was worth $400 but he sold it for 20% less than its value.  How much money came out of his pocket?
conversations.from: assistant
conversations.value: He loses 400*.2=$80 on the PlayStation
  So he sells it for 400-80=$320
  The computer cost 700+200=$900
  So he was 900-320=$580 out of pocket