Two engineering teams, A and B, are building a 720-meter-long tunnel. They work from both ends at the same time. The first team digs 14.5 meters a day, and the second team digs 15.5 meters a day. How many days will it take to dig this tunnel?
甲乙两个工程队修一条长720米的隧道，他们从两端同时开工，第一队每天开凿14.5米，第二队每天开凿15.5米，开凿这条隧道需要多少天？
<gadget id="calculator">14.5 + 15.5</gadget>
<output>30</output>

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

<result>24</result>