It is known that pools A and B contain 69 tons and 36 tons of water respectively. If the water in pool A flows into pool B at a rate of 2 tons per minute, then after how many minutes, the water in pool B will be twice that of pool A.
已知甲、乙两池分别有水69吨和36吨．如果甲池中的水以每分钟2吨的速度流入乙池，那么，多少分钟后，乙池中的水是甲池的2倍．
<gadget id="calculator">69 * 2</gadget>
<output>138</output>

<gadget id="calculator">138 - 36</gadget>
<output>102</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

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

<gadget id="calculator">102 / 6</gadget>
<output>17</output>

<result>17</result>