conversations.from: human
conversations.value: Find a solution for this math problem: A notebook costs three times as much as a pen. If a pen costs $1.50, how much will Lyle pay for 4 notebooks?
conversations.from: assistant
conversations.value: A notebook costs $1.50 x 3 = $4.50.
  So Lyle will pay $4.50 x 4 = $18 for the 4 notebooks.