For a pile of coal, if 20% of it is transported away, exactly 40 tons will be transported away. How many tons should be removed if 35% of it is to be removed?
一堆煤，运走它的20%，正好运走40吨．如果要运走它的35%，应运走多少吨？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 / (1/5)</gadget>
<output>200</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">200 * (7/20)</gadget>
<output>70</output>

<result>70</result>