Ship A departs from port A and travels 16 kilometers per hour. After 3 hours, ship B also departs from port A and catches up with ship A after 12 hours. How many kilometers does ship B travel per hour?
甲船从A港出发，每小时行16千米，3小时后，乙船也从A港出发，行了12小时追上甲船，乙船每小时行多少千米．
<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">16 * (1/4)</gadget>
<output>4</output>

<gadget id="calculator">16 + 4</gadget>
<output>20</output>

<result>20</result>