Use a batch of cloth to make 20 pieces of the same jacket or 30 pieces of trousers. So how many sets of such clothes can be made with this batch of cloth?
用一批布做同样的上衣20件或者裤子30件．那么用这批布可以做这样的衣服多少套？
<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>