conversations.from: human
conversations.value: Thirty-six marbles are divided between Mario and Manny in the ratio 4:5. If Manny decided to give 2 marbles to his brother, how many marbles does Manny have now?
  Give me a detailed solution.
conversations.from: assistant
conversations.value: The marbles are divided into 4 + 5 = 9 parts.
  Each part consists 36/9 = 4 marbles.
  So Manny had 5 parts x 4 = 20 marbles.
  After giving 2 marbles to his brother, he now has 20 - 2 = 18 marbles left.