The bottle contains 1 kg of 15% alcohol solution, and now 0.1 kg and 0.4 kg of two alcohol solutions A and B are poured in respectively, so that the concentration of the alcohol solution in the bottle is reduced by 1%. If the concentration of type A alcohol solution is twice that of type B, what is the concentration of type B alcohol solution?
瓶中装有浓度为15%的酒精溶液1千克，现在又分别倒入0.1千克和0.4千克的两种酒精溶液A和B，使得瓶中的酒精溶液浓度降低了1%．如果A种酒精溶液的浓度是B种的2倍，那么B种酒精溶液的浓度是多少．
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(3/20) - (1/100)</gadget>
<output>7/50 = around 0.14</output>

<gadget id="calculator">1 * 1_000</gadget>
<output>1_000</output>

<gadget id="calculator">0.1 * 1 * 1_000</gadget>
<output>100</output>

<gadget id="calculator">0.4 * 1 * 1_000</gadget>
<output>400</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">(3/20) * 1 * 1_000</gadget>
<output>150</output>

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

<gadget id="calculator">1_000 / 2</gadget>
<output>500</output>

<gadget id="calculator">0.4 * 1 * 500</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">1_000 / 100</gadget>
<output>10</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">(1/5) * 0.1 * 1 * 5</gadget>
<output>0.1</output>

<result>0.1</result>