A project, A and B cooperate to complete it in 6 days, A can complete the whole project in 3 days (3/10), how many days can B alone complete half of the project?
一项工程，甲乙两合作6天完成，甲独做3天完成全部工程的(3/10)，乙独做几天可以完成全部工程的一半？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(3/10) / 3</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) - (1/10)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/2) / (1/15)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>