conversations.from: human
conversations.value: Matias is a salesman in a bookstore. He sold 7 books on Tuesday and three times as many on Wednesday. If the sales from Wednesday were tripled on Thursday, how many books did Matias sell during these three days combined?
  Work out the solution step by step.
conversations.from: assistant
conversations.value: Matias sold 7 * 3 = 21 books on Wednesday, as he sold three times more books than on Tuesday.
  The sales from Wednesday were tripled on Thursday, which means Matias sold then 21 * 3 = 63 books.
  That means in total Matias sold 7 + 21 + 63 = 91 books during these three days.