A computer desk is sold for 255 yuan after a 15% discount, how much cheaper than the original price?
一台电脑桌打八五折后卖255元，比原价便宜了多少元？
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">255 / (17/20)</gadget>
<output>300</output>

<gadget id="calculator">300 - 255</gadget>
<output>45</output>

<result>45</result>