There are 3 buckets, if 4 kilograms are poured out of each bucket, then the weight of the water remaining in the 3 buckets is exactly equal to the weight of the original 1 bucket of water, how much water was originally contained in each bucket?
有3个水桶，如果从每桶中倒出4千克，那么3桶里剩下的水的重量正好等于原来1桶水的重量，原来每桶装多少水？
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

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

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<result>6</result>