A boat travels upstream in a 176km river at a speed of 30km/h. It takes 11 hours. How many hours does it take to return to the original place?
一只船以30km/h的速度在176km的河中逆水而行，用了11小时，返回原处需要几小时？
<gadget id="calculator">176 / 11</gadget>
<output>16</output>

<gadget id="calculator">30 - 16</gadget>
<output>14</output>

<gadget id="calculator">30 + 14</gadget>
<output>44</output>

<gadget id="calculator">176 / 44</gadget>
<output>4</output>

<result>4</result>