A pile of coal has been burned for 18 days, and there are still 12 tons left. If you save 0.2 tons per day, the remaining coal can be burned for 12 days. How many tons of coal are there in total?
一堆煤，已经烧了18天，还剩12吨．如果每天节约0.2吨，剩下的煤还可以烧12天，这堆煤共有多少吨？
<gadget id="calculator">12 / 12</gadget>
<output>1</output>

<gadget id="calculator">1 + 0.2</gadget>
<output>1.2</output>

<gadget id="calculator">1.2 * 18</gadget>
<output>21.6</output>

<gadget id="calculator">21.6 + 12</gadget>
<output>33.6</output>

<result>33.6</result>