The Milk Promotion Paradox

A man walks into a store and spots a strange promotion sign. One bottle of milk:

$1. But if you buy 5 bottles… the price is $7. He thinks,

“Wait, what kind of deal costs more?” So he decides to buy 5 individual

bottles, each for $1 — a total of $5. Feeling clever, he says to the cashier:

“I’m smart. Buying them separately is cheaper than your so-called promotion!” The cashier smiles

and replies: “I know. But you just bought 5 bottles of milk… when you only came

in for one.”