There are 8 badmintons in a tube, each badminton is 3 yuan, and the physical education teacher spent 720 yuan to buy badmintons. How many barrels of badminton did he buy?
一筒羽毛球有8个，每个羽毛球3元，体育老师买羽毛球用了720元．他买了多少筒羽毛球？
<gadget id="calculator">3 * 8</gadget>
<output>24</output>

<gadget id="calculator">720 / 24</gadget>
<output>30</output>

<result>30</result>