5.6 kg of ink can be loaded with 3 large bottles and 5 small bottles, and 2.4 kg of ink can be loaded with 1 large bottle and 3 small bottles. Then how many kilograms of ink can be filled with 2 large bottles and 1 small bottle.
用3个大瓶和5个小瓶可装墨水5.6千克，用1个大瓶和3个小瓶可装墨水2.4千克．那么用2个大瓶和1个小瓶可装墨水多少千克．
<gadget id="calculator">2.4 + 0.4</gadget>
<output>2.8</output>

<result>2.8</result>