It used to take (11/15) hours for Master Li to process a part, but now it takes (5/12) hours, how many hours has been shortened?
李师傅加工一个零件，原来要用(11/15)小时，现在要用(5/12)小时，缩短了多少小时？
<gadget id="calculator">11 / 15</gadget>
<output>11/15 = around 0.733333</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">(11/15) - (5/12)</gadget>
<output>19/60 = around 0.316667</output>

<result>19/60 = around 0.316667</result>