How To Cutting Of Chudidar Pyjama

Imagine that you have purchased a product manager urgently, no Whatever it is.
Come to the store and we found the following offers:

• A 24-pack for 9 euros.
• A package of 36 units per 13 euros.

A quick count tells me the big package is cheaper. For added security, do the math:

• 9 / 24 = 0.375 € / unit
• 13 / 36 = 0.361 € / unit

So I choose the largest package being the most economical. But when I get it I see a bid. For the purchase of a package (no matter how small big) they give you other 12 units is attached. Does it make this gift? Does a gift should change into something that you buy?

Consider what I take and not what is supposed to buy. Because the store says "we give you more x" does not mean anything. What you may be getting into the price anyway. So I go back to calculate the price per unit, taking into account the total of what actually took me:

• 24 +12 = 36, 9 / 36 = 0.25 € / unit
• 36 +12 = 48, 13/48 = 0.27 € / unit

Well, well. I almost deceiving. The cheapest deal is small. Right? Would you be if the gift you give what you pay the original? What if they go together in the same package? Does it matter that is a bonus or not? Do they make many pitfalls of these stores? Am I doing something wrong?