From the figure it is clear that liquid 1 floats on liquid 2 . The lighter liquid floats over heavier liquid. Therefore we can conclude that ρ1<ρ2 Also ρ3<ρ2 otherwise the ball would have sink to the bottom of the jar. Also ρ3>ρ1 otherwise the ball would have floated in liquid 1 . From the above discussion we conclude that ρ1<ρ2<ρ3.