Use a glass to pour water into an empty bottle. If 3 cups of water are poured in, the total weight of the bottle is 440 grams; if 5 cups of water are poured in, the total weight of the bottle is 600 grams. How many grams does an empty bottle weigh?
用一个杯子向一个空瓶里倒水．如果倒进3杯水，连瓶共重440克；如果倒进5杯水，连瓶共重600克，一个空瓶重多少克？
<gadget id="calculator">600 - 440</gadget>
<output>160</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">160 / 2</gadget>
<output>80</output>

<gadget id="calculator">80 * 3</gadget>
<output>240</output>

<gadget id="calculator">440 - 240</gadget>
<output>200</output>

<result>200</result>