A piece of clothing with an original price of 200 yuan is now on sale at a 15% discount. How much is it cheaper?
一件原价200元的衣服，现在八五折出售，便宜了多少元．
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">200 * (3/20)</gadget>
<output>30</output>

<result>30</result>