The east and west ports are 220 kilometers apart. At 9:00 am, a cargo ship sails from the east port to the west port; at 1:00 pm, a passenger ship sails from the west port to the east port. How many kilometers per hour does the passenger ship travel?
东西两港相距220千米，上午9时，一只货船从东港开往西港；下午1时，一只客船从西港开往东港，在下午5时两船相遇，货船每小时行15千米，客船每小时行多少千米？
<gadget id="calculator">17 - 9</gadget>
<output>8</output>

<gadget id="calculator">15 * 8</gadget>
<output>120</output>

<gadget id="calculator">220 - 120</gadget>
<output>100</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<result>25</result>