Two ferry boats sail from the south bank to the north bank. The first boat sails first at a speed of 30 kilometers per hour. The second boat sails 12 minutes later at a speed of 40 kilometers per hour. As a result, the two boats arrive at the same time. Find the north and south coasts How far apart?
两艘渡船从南岸开往北岸，第一艘船以每小时30千米的速度先开，第二艘船晚开12分钟，速度为每小时40千米，结果两船同时到达，求南北岸相距多远？
<gadget id="calculator">40 - 30</gadget>
<output>10</output>

<gadget id="calculator">0.2 / 10</gadget>
<output>0.02</output>

<gadget id="calculator">30 * 0.02 * 40</gadget>
<output>24</output>

<result>24</result>