Container A can hold 200 milliliters of water, which is 50 milliliters more than container B. The capacity of container C is twice that of container B. How many milliliters of water can container C hold?
甲容器可盛水200毫升，比乙容器多盛水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>