Container A can hold 200ml of water, container B can hold 50ml more water than container A, and container C can hold twice the capacity of container B, how much water can container C hold?
甲容器可盛水200毫升，乙容器比甲容器多盛水50毫升，丙容器的容量是乙容器的2倍，丙容器可盛水多少毫升？
<gadget id="calculator">200 + 50</gadget>
<output>250</output>

<gadget id="calculator">250 * 2</gadget>
<output>500</output>

<result>500</result>