Two people, A and B, can complete a job in 2 hours. If it takes 6 hours for A to complete the work alone, then how many times more efficient is the work done by B alone than the work done by A alone.
甲乙两人合作2小时可以完成一项工作．如果由甲单独完成需要6小时，那么由乙单独完成的工作效率是甲单独完成的工作效率的多少倍．
<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">(1/2) - (1/6)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) / (1/2)</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>