The cafeteria burns (11/20) tons of coal in three days, and (3/20) tons on the first and second days respectively. How many tons of coal are burned on the third day?
食堂三天共烧煤(11/20)吨，第一、二两天各烧(3/20)吨，第三天烧煤多少吨？
<gadget id="calculator">11 / 20</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(11/20) - (3/20) - (3/20)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>