There is some water in an iron bucket, and the water is tripled, and the bucket weighs 9 kg; the water is added to 8 times, and the bucket weighs 19 kg. How many kilograms does the water weigh?
在一个铁桶里装有一些水，把水加到原来的3倍，连桶重9千克；把水加到原来的8倍，连桶重19千克．原来水重多少千克？
<gadget id="calculator">19 - 9</gadget>
<output>10</output>

<gadget id="calculator">8 - 3</gadget>
<output>5</output>

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

<result>2</result>