In a stationery store, all products are sold at a 15% discount. A table tennis racket used to cost 30 yuan per pair. How much cheaper can I buy now?
某文化用品店，所有商品八五折出售，一种乒乓球拍，原来每副售价30元，现在买可以便宜多少元？
<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">30 * (3/20)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>