During the "May 1st" period, merchants are conducting promotional activities, and a piece of clothing is sold at a 15% discount. Now it costs 170 yuan. How much is it cheaper than before?
"五一期间"商家搞促销活动，一件衣服打八五折出售，现在卖170元，现在比原来便宜多少元？
<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>