Pool A contains 168 tons of water, and pool B contains 92 tons of water. Both pools discharge 2 tons of water per hour. After how many hours, the tonnage of pool A is three times that of pool B.
A水池有168吨水，B水池有92吨水，两水池每小时都排出2吨水，经过多少小时后，A水池的吨数是B水池的3倍．
<gadget id="calculator">3 * 92</gadget>
<output>276</output>

<gadget id="calculator">276 - 168</gadget>
<output>108</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 - 2</gadget>
<output>4</output>

<gadget id="calculator">108 / 4</gadget>
<output>27</output>

<result>27</result>