A and B are two buckets containing sugar water. Bucket A contains 60 kg of sugar water with a sugar content of 40%; bucket B contains 40 kg of sugar water with a sugar content of 20%. To make the sugar content of two buckets of sugar water equal, how many kilograms of sugar water should be exchanged between the two buckets?
甲、乙两只装糖水的桶，甲桶有糖水60千克，含糖率为40%；乙桶有糖水40千克，含糖率为20%．要使两桶糖水的含糖率相等，需把两桶的糖水相互交换多少千克？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 60</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">60 * (1/150)</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(1/5) / 40</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">40 * (1/200)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/5) - (1/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/5) / 40</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(1/5) / 60</gadget>
<output>1/300 = around 0.003333</output>

<gadget id="calculator">(1/100) - (1/300) - (1/200)</gadget>
<output>1/600 = around 0.001667</output>

<gadget id="calculator">(1/150) + (1/600)</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">(1/5) / (1/120)</gadget>
<output>24</output>

<result>24</result>