The two piles of coal, A and B, weigh 35 tons in total. If each is used up (1/5), there will be 12 tons left in pile A, and how many tons will be left in pile B?
甲、乙两堆煤共重35吨，如果各用掉(1/5)，甲堆还剩12吨，乙堆还剩多少吨？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 / (4/5)</gadget>
<output>15</output>

<gadget id="calculator">35 - 15</gadget>
<output>20</output>

<gadget id="calculator">20 * (4/5)</gadget>
<output>16</output>

<result>16</result>