There is a pile of coal, half of which is removed on the first day, and the remaining half is removed on the second day. At this time, there are still 12 tons left. How many tons are there in this pile of coal?
有一堆煤，第一天运走全部的一半，第二天运走剩下的一半，这时还剩下12吨，这堆煤共有多少吨？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 / (1/2) / (1/2)</gadget>
<output>48</output>

<result>48</result>