conversations.from: human
conversations.value: Cindy had 20 marbles which is 5 more than what Lisa had. If Cindy gave her 12 marbles, how many more marbles does Lisa have now?
  Find the solution.
conversations.from: assistant
conversations.value: Lisa had 20 - 5 = 15 marbles.
  Since Cindy gave 12 marbles, then she only has 20 - 12 = 8 marbles left.
  Since Lisa received 12 marbles, then Lisa has 15 + 12 = 27 marbles now.
  Hence, Lisa has 27 - 8 = 19 marbles more than Cindy.