A project is completed in 8 days by A alone, and B does 1/10 of the project every day. The two work together to complete half of the project. How many days will it be completed?
一项工程，甲独做8天完成，乙每天做这项工程的(1/10)，两人合做工程的一半，几天完工？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) + (1/10)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">(1/2) / (9/40)</gadget>
<output>20/9 = around 2.222222</output>

<result>20/9 = around 2.222222</result>