It takes A 4 days and B 5 days to complete the same job alone, how much is A's work efficiency than B's.
单独完成同一件工作，甲要4天，乙要5天，甲的工作效率是乙的多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) / (1/5)</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>