conversations.from: human
conversations.value: A certain tree was 100 meters tall at the end of 2017. It will grow 10% more than its previous height each year. How long has the tree grown from 2017 until the end of 2019?
  How to solve this?
conversations.from: assistant
conversations.value: At the end of 2018, the tree will grow 100 x 10/100 = 10 meters more.
  Thus, its height at the end of 2018 is 100 + 10 = 110 meters.
  At the end of 2019, the tree will grow 110 x 10/100 = 11 meters more.
  So, its height at the end of 2019 is 110 + 11 = 121 meters.
  Therefore, the tree has grown 121 - 100 = 21 meters.