conversations.from: human
conversations.value: Frances sells 20 cupcakes for $2 for each cupcake and  40  cookies at $1 each.  She buys five trays at $4 for each tray. How much money does Frances have left?
  How to solve this?
conversations.from: assistant
conversations.value: 20 cupcakes cost 20 x $2 =$40.
  40 cookies cost 40 x $1 = $40.
  So, Frances earns $40 + $40 = $80 for selling cupcakes and cookies.
  The cost of five trays is 5 x $4 = $20.
  Therefore, France will have $80 - $20 = $60 left.