I ran across this thing over a year ago, and finally gave up on it.  Mull it over a while.  What's the deal?

[b]Three guys ordered a couple pizzas for $30. The delivery boy brought the pizzas, and the three guys each gave him a $10 bill.

The pizza boy went away disappointed that he didn't get a tip. He took the $30 back to the manager.

However, the manager said that there was a mistake and the pizzas were only supposed to cost $25, so he gave the delivery boy five $1 bills to return to the customers.

   
On the way, the boy remembered that these three guys didn't give him a tip. Since he couldn't split five dollars three ways evenly anyway, he kept two dollars for himself and gave each of the three guys a dollar back.

Do you follow this so far? Everything is fine, right?

Consider this:

Each guy paid a 10 dollar bill for the pizzas, and got back a dollar in change. That means they each paid 9 dollars for the pizzas.

$10-$1=$9



The price of the pizza was 3 times $9, or $27.

3 x $9 = $27

The pizza delivery boy collected a $2 tip. This brings the total cost of the pizzas, including the tip, to $29.

$27 + $2 = $29

But the guys paid $30 for the pizzas. $30

So, who ended up with the other dollar?

Can you explain what went wrong? It could happen to you![/b]

Mental illusion.

You're confused by the fact that this mix up occurred away from their door.

see it this way...

They give him 30 bucks.

He says nope, supposed to be 25 bucks, gives em back 3 bucks, and pockets two.

So, now it's 25 that they paid total. 25/3 = 8.333(infinite) that they paid each.

They each paid 8.333 total, not 9(10-1). They have 3 bucks refund total(one apiece), and the delivery kid has the other 2

25 at the shop, 3 back to the dudes, 2 with the kid.

Cause they didn't actually pay 9 bucks, see?

Juggernaut beat me to it. see his reply above.

And Rosie O'donut says we don't need math.  Makes me want to deliver pizzas to her and rip her off on the tip.

Do it with 30 real dollars, and right in front of your face, one will disappear!

What type of pizza's did they order?

What?  No beer?

No, they each did pay $9. 10-1=9

This is the part where they mix up the numbers and get you confused:



The total cost of the pizza to the three guys is $27, not $29.

$25 went to the manager, $2 went to the delivery boy.

Adding the $2 to the $27 the guys paid makes no sense. It is the "fuzzy math" G.W. warned you about.