A total of 2,500 tons of coal was transported to the power plant. After some of it was used, the remaining 40% was used. How many tons were used?
发电厂共运来2500吨煤，用去一部分后，还剩40%，用了多少吨．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2_500 * (3/5)</gadget>
<output>1_500</output>

<result>1_500</result>