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?
20% of $45 is (20/100)*$45 = $
<gadget id="calculator">(20/100)*45</gadget>
<output>9</output>
9.
The price of the textbook in other bookshops cost $9 less than $45 which is $45-$9 = $
<gadget id="calculator">45-9</gadget>
<output>36</output>
36.
Three textbooks from the school bookshop would cost $45*3 = $
<gadget id="calculator">45*3</gadget>
<output>135</output>
135.
Three textbooks from another bookshop would cost $36*3 = $
<gadget id="calculator">36*3</gadget>
<output>108</output>
108.
Peter can save $135-$108 = $
<gadget id="calculator">135-108</gadget>
<output>27</output>
27 by buying from another bookshop.

<result>27</result>