Three friends eat a restaurant. Their bill comes to $30 in total which they decide to split equally between them with each of them therefore paying $10 towards the total.The waitress takes the money and the bill to the cash and double checks the bill only to find that the restaurant has over charged. Thus the total bill is revised downwards to $25 and the waitress returns the $5 back to the three diners with an apology.

The diners are naturally grateful for her honesty and give her two dollars of this $5 refund as a tip to her. The diners then split the remaining $3 equally between them.Thus the situation is that whilst each diner originally paid $10 each for their meal, now they have only paid $9 each.

$9 times 3 = $27
Plus the $2 tip to the waitress =$29

Where has the missing $1 gone????

This one has me puzzled. It is so counter intuitive.

The diners paid 25/3$ each.
Each diner paid
8 1/3$ + 3/3$ + 2/3$ = 10$
There is no missing 1$.

Yes, you got it. An easy puzzle for someone mathematically minded, but surprisingly challenging for many lay people especially if presented verbally.

This is an old but popular puzzle told with many differing stories.

But can this be turned into a neat little magic trick? Just like the age old liar/truth teller puzzle has resulted in some amazing routines being released.

Can it be turned into a neat little magic trick? It already has been: https://www.youtube.com/watch?v=Im1ddjyAgOw

Wow..thanks for the reference, Scott. And sorry 'bout my ignorance.

The original post says

"$9 times 3 = $27
Plus the $2 tip to the waitress =$29"

The misleading piece / error is the word "plus." Why are we adding the $2? The $2 is ALREADY accounted for in the $27. It is more accurate to say "$9 times 3 = $27, MINUS the $2 tip = $25, the cost of the meal." Of course, when stated that way, there is no mystery.

It's the word "plus" that gets people. There's no reason to be re-adding the $2 that is already in the $27.