conversations.from: human
conversations.value: John had $200. He gave 3/8 of his money to his mother and 3/10 to his father. How much money did John have left?
  How to solve this?
conversations.from: assistant
conversations.value: John's mother received 3/8 x $200 = $75.
  His father got 3/10 x $200 = $60.
  Thus, John gave a total of $75 + $60 = $135.
  Therefore, John had $200 - $135 = $65 left.