There is a batch of coal in the cafeteria. If 45% of this batch of coal is used up, and the rest is 200 kilograms more than the used one, how many kilograms of coal are there in the cafeteria?
食堂有一批煤，如果用去这批煤的45%，剩下的比用去的多200千克，那么食堂原来有煤多少千克？
<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20) - (9/20)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">200 / (1/10)</gadget>
<output>2_000</output>

<result>2_000</result>