A piece of work needs 10 days to be completed by A alone, and B's work efficiency is (2/3) of A's. How many days can A and B cooperate to complete the task?
一件工作，甲单独完成需要10天，乙的工作效率是甲的(2/3)．甲乙合作几天可以完成任务？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">10 * (3/2)</gadget>
<output>15</output>

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

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

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

<result>6</result>