There is a piece of bronze, which is made of three metals: copper, tin and zinc. Among them, copper accounts for (21/25) of the total weight, tin accounts for (1/20) of the total weight, and what percentage of zinc accounts for the total weight?
有一块青铜，是由铜、锡和锌三种金属熔合而成的．其中铜占总重量的(21/25)，锡占总重量的(1/20)，锌占总重量的几分之几？
<gadget id="calculator">21 / 25</gadget>
<output>21/25 = around 0.84</output>

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

<gadget id="calculator">1 - (21/25) - (1/20)</gadget>
<output>11/100 = around 0.11</output>

<result>11/100 = around 0.11</result>