There is a pile of coal, 20% of which is removed on the first day and 3/4 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20%，第二天运走(3/4)，这时还剩下12吨，这堆煤共有多少吨？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (1/5) - (3/4)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">12 / (1/20)</gadget>
<output>240</output>

<result>240</result>