The guest house spent 500 yuan to buy 15 beds of towels and quilts, leaving 20 yuan left. How much is the average price of towels per bed?
招待所用500元钱买15床毛巾被，还剩20元钱．平均每床毛巾被的价格是多少元？
<gadget id="calculator">500 - 20</gadget>
<output>480</output>

<gadget id="calculator">480 / 15</gadget>
<output>32</output>

<result>32</result>