A project is done alone, A takes 15 days to complete, and B takes 30 days to complete. At the beginning, the two work together. Because of work needs, A is transferred halfway. As a result, B and B took 16 days to complete. How many days did Team A work?
一项工程单独做，甲要15天完成，乙要30天完成，开始二人一起干，因工作需要甲中途调走，结果乙一共用了16天完成．甲队工作了几天？
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/30) * 16</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">1 - (8/15)</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(7/15) / (1/15)</gadget>
<output>7</output>

<result>7</result>