conversations.from: human
conversations.value: Eve had 20 pieces of pomelos. After giving her friend some pomelos, Eve is left with 1/4 of the pomelos she originally had. How many pomelos did Eve give away?
  Give me a detailed solution.
conversations.from: assistant
conversations.value: Eve is left with 20 x 1/4 = 5 pieces of pomelos.
  So she gave away 20 - 5 = 15 pieces of pomelos to her friend.