A container contains 10 liters of pure alcohol. After pouring out 2.5 liters, fill it up with water, pour out another 5 liters, and then fill it up with water. What is the concentration of the solution in the container at this time?
一容器内装有10升纯酒精，倒出2.5升后，用水加满，再倒出5升，再用水加满，这时容器内的溶液的浓度是多少．
<gadget id="calculator">10 - 2.5</gadget>
<output>7.5</output>

<gadget id="calculator">7.5 / 10</gadget>
<output>0.75</output>

<gadget id="calculator">0.75 * 5</gadget>
<output>3.75</output>

<gadget id="calculator">7.5 - 3.75</gadget>
<output>3.75</output>

<gadget id="calculator">3.75 / 10</gadget>
<output>0.375</output>

<result>0.375</result>