A pile of coal is planned to be burned for 10 days, but actually burns (1/5) less tons per day than planned, so that it can be burned for 5 more days. How many tons is there in this pile of coal?
一堆煤计划烧10天，实际每天比计划少烧(1/5)吨，这样可以多烧5天，这堆煤有多少吨？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">10 * (1/5)</gadget>
<output>2</output>

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

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">5 - 10</gadget>
<output>-5</output>

<gadget id="calculator">10 + (-5)</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">10 * (3/5)</gadget>
<output>6</output>

<result>6</result>