conversations.from: human
conversations.value: Explain how to solve this math problem: A pen costs as much as a pencil and eraser combined. A pencil costs $1.20 and an eraser costs $0.30. How much will 8 pens cost?
conversations.from: assistant
conversations.value: A pen costs $1.20 + $0.30 = $1.50.
  So, 8 pens cost $1.50 x 8 = $12.