(Additional question) A container is exactly filled with 10 liters of pure alcohol, pour out 3 liters and then fill it up with water, then pour out 4.5 liters and then fill it up with water, what is the concentration of the solution in the container at this time?
(附加题)一个容器正好装满10升纯酒精，倒出3升后用水加满，再倒出4.5升后，再用水加满，这时容器中溶液的浓度时多少？
<gadget id="calculator">10 - 3</gadget>
<output>7</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">4.5 * (7/10)</gadget>
<output>3.15</output>

<gadget id="calculator">10 - 3 - 3.15</gadget>
<output>3.85</output>

<gadget id="calculator">3.85 / 10</gadget>
<output>0.385</output>

<result>0.385</result>