The master and the apprentice produce the same kind of parts, the master produces half of the total at an efficiency of 8 per hour, and the remaining half at an efficiency of 12 per hour; 8, in the second half of the working time, do 12 per hour, until it is finished, what fraction of the master's time is the time spent by the apprentice?
师徒两人生产数量相同的一种零件，师傅以每小时8个的效率生产了总量的一半，又以每小时12个的效率生产余下的一半；而徒弟前一半的工作时间每小时做8个，后一半的工作时间每小时做12个，直到做完为止，问徒弟所用赶时间是师傅的几分之几？
<gadget id="calculator">8 + 12</gadget>
<output>20</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">(1/2) / 8</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">(1/2) / 12</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">(1/16) + (1/24)</gadget>
<output>5/48 = around 0.104167</output>

<gadget id="calculator">2 / (5/48)</gadget>
<output>96/5 = around 19.2</output>

<gadget id="calculator">(1/20) * (96/5)</gadget>
<output>24/25 = around 0.96</output>

<result>24/25 = around 0.96</result>