The bottle contains 1000 grams of 15% alcohol solution. Now pour 100 grams and 400 grams of A and B alcohol solutions respectively, and the concentration in the bottle becomes 14%. It is known that alcohol solution A is twice as concentrated as alcohol solution B. So what is the concentration of type A alcohol solution?
瓶中装有浓度为15%的酒精溶液1000克．现在又分别倒入100克和400克的A，B两种酒精溶液，瓶里的浓度变成了14%．已知A种酒精溶液是B种酒精溶液浓度的2倍．那么A种酒精溶液的浓度是多少？
<gadget id="calculator">14 / 100</gadget>
<output>7/50 = around 0.14</output>

<gadget id="calculator">1_000 + 100 + 400</gadget>
<output>1_500</output>

<gadget id="calculator">(7/50) * 1_500</gadget>
<output>210</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 1_000</gadget>
<output>150</output>

<gadget id="calculator">210 - 150</gadget>
<output>60</output>

<gadget id="calculator">400 / 2</gadget>
<output>200</output>

<gadget id="calculator">100 + 200</gadget>
<output>300</output>

<gadget id="calculator">60 / 300</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

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

<result>1/5 = around 0.2</result>