conversations.from: human
conversations.value: This math problem has got me stumped: Tina is getting $20 for each book she sells. If she realizes a $120 profit on her sales, how many people have she sold the books to if each book costs $5 to make and every customer buys 2 at a time?
  Can you show me the way?
conversations.from: assistant
conversations.value: First, we need to determine the profit per book. To do this, we perform 20-5=15 dollars in profit per book.
  Next, we divide the total sales by the profit per book, performing 120/15=8 books sold in total.
  Since the books are sold 2 at a time, we divide the number sold by 2 to find the total number of people sold to, performing 8/2=4 people in total.