25% of a batch of coal has been used up, and there are 60 tons left. How many tons of this batch of coal are there?
一批煤用去25%，还剩60吨，这批煤共有多少吨？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">60 / (3/4)</gadget>
<output>80</output>

<result>80</result>