An everyday situation for a retailer

Consider the value of 'labeling+service taxes' be $x$ . Then price of 'contents+bottle' is $x+2$ .

Thus,

$x+(x+2)=2.20 \\ \implies 2x+2=2.20 \\ \implies x+1=1.10 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \small\color{#3D99F6}{\text{Dividing both sides of the equation by } 2} \\ \implies x=0.10$

$\therefore$ Price of 'contents+bottle' is $x+2 = 0.10+2 = \boxed{2.10}$ .

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A common mistake that one makes in this problem is that we suspect that the answer is $2$ for 'contents+bottle' and $0.20$ for 'labeling+service taxes', but the difference between the values of the two, in this case, turns out to be $1.80$ and not $2$ .