The school sports room bought 15 new badminton rackets, and the number of newly bought table tennis rackets is 20% less than the number of newly bought badminton rackets. How many new pairs of table tennis rackets are bought?
学校体育室新买了15副羽毛球拍，新买的乒乓球拍数比新买的羽毛球拍数少20%，新买乒乓球拍多少副？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 * (1/5)</gadget>
<output>3</output>

<gadget id="calculator">15 - 3</gadget>
<output>12</output>

<result>12</result>