It takes 15 hours for A to do a project alone, and 12 hours for B to do it alone. What percentage of A's work efficiency is B's work efficiency?
一项工程甲单独做需15小时，乙单独做只需12小时．甲的工作效率是乙的工作效率的百分之几？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/15) / (1/12)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>