There are 10 barrels of gasoline, if 20 kilograms are taken out of each barrel, the weight of the remaining gasoline in the 10 barrels is exactly equal to the weight of the original 6 barrels of gasoline. How many kilograms does each barrel of gasoline weigh?
有10桶汽油，如果每桶中取出20千克，10个油桶里剩下的汽油的重量正好等于原来6桶汽油的重量．原来每桶汽油重多少千克？
<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">10 / 4</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">20 * (5/2)</gadget>
<output>50</output>

<result>50</result>