schoolbag is 60 yuan after a 25% discount. How much is this schoolbag lower than the original price?
一种书包打七五折后是60元，这个书包比原价降了多少元？
<gadget id="calculator">75 / 100</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">60 / (3/4)</gadget>
<output>80</output>

<gadget id="calculator">80 - 60</gadget>
<output>20</output>

<result>20</result>