A batch of coal burns 60 tons, exactly (2/7) of this batch of coal is burned, how many tons of this batch of coal?
一批煤，烧去60吨，正好烧去这批煤的(2/7)，这批煤多少吨？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">60 / (2/7)</gadget>
<output>210</output>

<result>210</result>