conversations.from: human
conversations.value: Find a solution for this math problem: Chris bought 8 movies on DVD for $12 each and 4 movies on Blu-ray for $18 each. What is the average price he paid per movie?
conversations.from: assistant
conversations.value: He spent a total of 8 * $12 + 4 * $18 = $168
  He bought a total of 8 + 4 = 12 movies.
  The average price is $168 / 12 = $14 per movie.