The selling price of a piece of clothing is 170 yuan with a 15% discount. How much is this clothing cheaper than the original?
一件衣服打八五折出售的价格是170元，这件衣服比原来便宜了多少钱？
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">170 / (17/20)</gadget>
<output>200</output>

<gadget id="calculator">200 - 170</gadget>
<output>30</output>

<result>30</result>