There is a basket of apples, after selling (3/5), there are 12 kilograms left, so how many kilograms are there in this basket of apples?
有一筐苹果，卖出(3/5)后，还剩12千克，那么这筐苹果原来有多少千克．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">12 / (2/5)</gadget>
<output>30</output>

<result>30</result>