The children's clothing factory has some fabrics. If all of them are used to make jackets, 20 pieces can be made; if all of them are used to make pants, 30 pieces can be made. If a top and a pair of pants are used as a suit, how many suits can these fabrics make?
童装厂有一些布料，如果全部用来做上衣，可以做20件；如果全部用来做裤子，可以做30条．如果将一件上衣和一条裤子作为一套衣服，那么这些布料可以做多少套衣服？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/20) + (1/30)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / (1/12)</gadget>
<output>12</output>

<result>12</result>