A factory uses 24 tons of coal this month, which is 12% less than last month. Find the number of tons of coal used last month. What is the column type.
某工厂本月份用煤24吨，比上个月节约12%，求上个月用煤多少吨．列式是多少．
<gadget id="calculator">12 / 100</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">1 - (3/25)</gadget>
<output>22/25 = around 0.88</output>

<gadget id="calculator">24 / (22/25)</gadget>
<output>300/11 = around 27.272727</output>

<result>300/11 = around 27.272727</result>