A chicken, a duck, a goose, and a dog weigh 28kg in total. The chicken weighs the same as the duck, the goose is three times the mass of the duck, and the dog is three times the mass of the goose. What is the weight of the goose in kg?
鸡、鸭、鹅、狗各一只，一共重28kg，鸡和鸭一样重，鹅是鸭的质量的3倍，狗是鹅的质量的3倍，鹅重多少kg．
<gadget id="calculator">1 + 1 + 3 + 9</gadget>
<output>14</output>

<gadget id="calculator">28 / 14</gadget>
<output>2</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<result>6</result>