If 3 large bottles and 7 small bottles can hold 16.8 kg of water, and 5 large bottles and 11 small bottles can hold 27.2 kg of water, then how much water can be contained in 1 large bottle and 2 small bottles?
如果3个大瓶和7个小瓶能装水16.8千克，5个大瓶和11个小瓶能装水27.2千克，那么1个大瓶和2个小瓶能装水多少千克．
<gadget id="calculator">2.8 + 2.4</gadget>
<output>5.2</output>

<result>5.2</result>