There is a pool, 12 meters long, 8 meters wide, and 4.71 meters deep. Now use a water pump to pump water from the river to the pool. The diameter of the drainage pipe of the pump is 2 decimeters, and the velocity of water in the drainage pipe is 2 meters per second. How many hours does it take to fill the pool?
有一个水池，长12米，宽8米，深4.71米．现用一台抽水机从河里往水池里抽水．抽水机排水管直径2分米，排水管内水流速度为每秒钟2米．大约几小时能灌满水池？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 2 * 10 * 3_600</gadget>
<output>226_080</output>

<gadget id="calculator">1_000 / 226_080</gadget>
<output>25/5_652 = around 0.004423</output>

<gadget id="calculator">12 * 8 * 4.71 * (25/5_652)</gadget>
<output>2</output>

<result>2</result>