There is a ship 50 kilometers away from the port. Due to a leak in the cabin, seawater seeps into the ship at a rate of 2 tons per 5 minutes. When the total amount of seawater infiltrated into the cabin exceeds 60 tons, the ship will sink into the sea. Suppose the pump on board can discharge 12 tons of seawater overboard per hour. The ship must sail towards the port at least at a speed of kilometers per hour to ensure that it will not sink before arriving at the port.
有一艘船距离港口50千米，由于船舱漏水，海水以每5分钟2吨的速率渗入船内．当船舱渗入的海水总量超过60吨时，此船将沉入海中．假若船上的抽水机每小时可将12吨的海水排出船外．此船至少要以每小时多少千米的速度驶向港口，以保证在抵达港口之前不会沉没．
<gadget id="calculator">60 / 5</gadget>
<output>12</output>

<gadget id="calculator">2 * 12</gadget>
<output>24</output>

<gadget id="calculator">24 - 12</gadget>
<output>12</output>

<gadget id="calculator">60 / 12</gadget>
<output>5</output>

<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<result>10</result>