The distance between two docks A and B is 112 kilometers. A boat travels upstream from dock B and arrives at dock A after 8 hours. It is known that the speed of the boat is 15 times the speed of water. How many hours?
甲、乙两个码头相距112千米，一只船从乙码头逆水而上，行了8小时到达甲码头，已知船速是水速的15倍，这只船从甲码头返回乙码头需要几小时？
<gadget id="calculator">112 / 8</gadget>
<output>14</output>

<gadget id="calculator">15 - 1</gadget>
<output>14</output>

<gadget id="calculator">112 / 8 / 14</gadget>
<output>1</output>

<gadget id="calculator">14 + 1 + 1</gadget>
<output>16</output>

<gadget id="calculator">112 / 16</gadget>
<output>7</output>

<result>7</result>