conversations.from: human
conversations.value: I'm stuck on this math problem: An author of a book got 6% of the total sales of the paper cover version of his books and 12% of the total sales of the hardcover version. If 32,000 copies of the paper cover version were sold at $0.20 each and 15,000 copies of the hardcover version were sold at $0.40 each, how much did the author earn?
  Can you help?
conversations.from: assistant
conversations.value: The total earnings for the paper cover version were $0.20 x 32 000 = $6,400.
  So, the author earned $6,400 x 6/100 = $384 from the paper cover version.
  The total earnings for the hardcover version were $0.40 x 15,000 = $6,000.
  So, the author earned $6,000 x 12/100 = $720 from the hardcover version.
  Therefore, the author earned a total of $384 + $720 = $1104.