conversations.from: human
conversations.value: The price of a math textbook in the school bookshop is $45. If those sold in bookshops outside the school cost 20% less, how much can Peter save by buying from other bookshops rather than the school's if he wants to buy 3 math textbooks?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: 20% of $45 is (20/100)*$45 = $9
  The price of the textbook in other bookshops cost $9 less than $45 which is $45-$9 = $36
  Three textbooks from the school bookshop would cost $45*3 = $135
  Three textbooks from another bookshop would cost $36*3 = $108
  Peter can save $135-$108 = $27 by buying from another bookshop