解设大瓶X ,小瓶为(2.5-X)
(X-0.6):(2.5-X+0.6)=3:2
(X-0.6):(3.1-X) =3:2
9.3-3X =2X-1.2
X =2.1
2.5-X =2.5-2.1=0.4
答,大瓶2.1千克,小瓶0.4千克