There are two buckets, A and B. Pour 20% of the water in bucket A into bucket B, which just fills bucket B (2/5). To fill bucket B, 6kg of water is needed. How many kilograms of water is there?
有甲、乙两个水桶，把甲桶里的水的20%倒入乙桶，刚好装了乙桶的(2/5)，要把乙桶加满，还需要6kg水，甲桶里原有水多少千克？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">6 / (3/5)</gadget>
<output>10</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/5) / (1/5)</gadget>
<output>2</output>

<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>