The total weight of a jigsaw puzzle and a rubik's cube is 3.5 kg. The total weight of a jigsaw puzzle and a toy train is 5.2 kg. If the total weight of a toy train and a rubik's cube is 6.08 kg, find the total weight of the jigsaw puzzle, the rubik's cube and the toy train.
Let 1 jigsaw puzzle be 1 J.
Let 1 rubik's cube be 1 R.
Let 1 toy train be 1 T.

1 J + 1 R = 3.5 --- (1)
1 J + 1 T = 5.2 --- (2)
1 T + 1 R = 6.08 --- (3)

(1) + (2) + (3)
1 J + 1 R + 1 J + 1 T + 1 T + 1 R = 3.5 + 5.2 + 6.08
2 J + 2 R + 2 T = 14.78
2(1 J + 1 R + 1 T) = 14.78 

1 J + 1 R + 1 T = 14.78 ÷ 2
1 J + 1 R + 1 T = 7.39

 Total weight of the jigsaw puzzle, the rubik's cube and the toy train = 7.39 kg

Answer(s): 7.39 kg