A pile of coal, the first time (2/5) was 50 tons more than the first time (2/3), the second time was 10 tons less than the first time (2/3), and the third time was 260 tons, just finished. How many tons is this pile of coal?
一堆煤，第一次运走(2/5)多50吨，第二次运走的比第一次的(2/3)少10吨，第三次运走260吨，正好运完．这堆煤共有多少吨？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">50 * (2/3)</gadget>
<output>100/3 = around 33.333333</output>

<gadget id="calculator">(100/3) - 10</gadget>
<output>70/3 = around 23.333333</output>

<gadget id="calculator">260 + 50 + (70/3)</gadget>
<output>1_000/3 = around 333.333333</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) * (2/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 - (2/5) - (4/15)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1_000/3) / (1/3)</gadget>
<output>1_000</output>

<result>1_000</result>