The distance between A and B ports is 480 kilometers. A cargo ship sails from port A to port B at 10 am, and a passenger ship sails from port B to port A at 2 pm. The passenger ship meets the cargo ship 12 hours after departure. A cargo ship travels 15 kilometers per hour, how many kilometers per hour does a passenger ship travel?
甲乙两港相距480千米．上午10时一艘货船从甲港开往乙港，下午2时一艘客船从乙港开往甲港，客船开出12小时后与货船相遇．货船每小时行15千米，客船每小时行多少千米？
<gadget id="calculator">12 - 10</gadget>
<output>2</output>

<gadget id="calculator">2 + 2 + 12</gadget>
<output>16</output>

<gadget id="calculator">15 * 16</gadget>
<output>240</output>

<gadget id="calculator">480 - 240</gadget>
<output>240</output>

<gadget id="calculator">240 / 12</gadget>
<output>20</output>

<result>20</result>