conversations.from: human
conversations.value: Maggie picked 40 apples. Kelsey picked 28 apples. Layla picked some apples, too. The three averaged 30 apples picked. How many did Layla pick?
  Give me a detailed solution.
conversations.from: assistant
conversations.value: Together, they picked 30*3=90.
  There are 40+28=68 accounted for.
  Then Layla picked 90-68=22.