A project can be completed in (1/5) hours alone, and B can be completed in (1/6) hours alone, how many hours can they complete together? what is the correct formula
一项工程，甲单独做(1/5)小时完成，乙单独做(1/6)小时完成，两人合做多少小时完成？正确的算式是多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

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

<gadget id="calculator">1 / (1/6)</gadget>
<output>6</output>

<gadget id="calculator">5 + 6</gadget>
<output>11</output>

<gadget id="calculator">1 / 11</gadget>
<output>1/11 = around 0.090909</output>

<result>1/11 = around 0.090909</result>