prompt: A new book sold 15 copies at the bookstore on Wednesday. On Thursday the book sold three times that many copies. On Friday the book sold one-fifth the number of copies it did on Thursday. How many copies of the book did the bookstore sell by Friday?
messages.content: A new book sold 15 copies at the bookstore on Wednesday. On Thursday the book sold three times that many copies. On Friday the book sold one-fifth the number of copies it did on Thursday. How many copies of the book did the bookstore sell by Friday?
messages.role: user
messages.content: On Thursday 15*3=<<15*3=45>>45 books were sold.
  On Friday 45/5=<<45/5=9>>9 books were sold
  Adding up all three days 15+45+9=<<15+45+9=69>>69 books were sold by Friday
  #### 69
messages.role: assistant