Type A alcohol contains 40% pure alcohol, type B alcohol contains 36% pure alcohol, and type C alcohol contains 35% pure alcohol. Mix these three alcohols together to obtain 11 kg of alcohol containing 38.5% pure alcohol. It is known that type B alcohol is 3 kg more than type C alcohol. So how many kilograms of alcohol is there?
甲种酒精含纯酒精40%，乙种酒精含纯酒精36%，丙种酒精含纯酒精35%．将这三种酒精混合在一起得到含纯酒精38.5的酒精11千克，已知乙种酒精比丙种酒精多3千克．那么甲种酒精有多少千克？
<gadget id="calculator">8 * 40</gadget>
<output>320</output>

<gadget id="calculator">3 * 36</gadget>
<output>108</output>

<gadget id="calculator">108 - 423.5</gadget>
<output>-315.5</output>

<gadget id="calculator">320 + (-315.5)</gadget>
<output>4.5</output>

<gadget id="calculator">2 * 40</gadget>
<output>80</output>

<gadget id="calculator">80 - 36 - 35</gadget>
<output>9</output>

<gadget id="calculator">4.5 / 9</gadget>
<output>0.5</output>

<gadget id="calculator">2 * 0.5</gadget>
<output>1</output>

<gadget id="calculator">11 - 1 - 3</gadget>
<output>7</output>

<result>7</result>