Lili and his three friends each bought two pairs of badminton rackets for a total of 320 yuan. How much is the average racket?
丽丽和他的3个朋友每人买了两副羽毛球拍，共花去320元．平均每副球拍多少钱？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">320 / 4 / 2</gadget>
<output>40</output>

<result>40</result>