Processing a batch of parts can be completed by A alone in 3 days. If B alone can spend (1/3) less time than A, then A can do the work completed by B in 4 days. How many days will it take to complete.
加工一批零件，甲独做3天可以完成，若乙独做，可比甲少花(1/3)时间，则乙做4天所完成的工作由甲来做，要多少天完成．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

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

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 4</gadget>
<output>2</output>

<gadget id="calculator">2 / (1/3)</gadget>
<output>6</output>

<result>6</result>