Three Irish guys go into a pub to have a few pints on St Paddy’s day. When they are ready to leave and pay their tab the bartender gives them a bill for exactly $30.00. Each guy gives him a tenner, and they leave.

A little later, the bartender realizes he has made a mistake. The bill was only $25.00, not $30.00. He grabs five $1 bills and rushes after the guys to give them back the money.

On his way out of the pub, the bartender has a thought… these guys did not give him a tip. He figures that since there is no way to split $5.00 evenly three ways anyhow, he will keep two dollars for himself and give them back three dollars.

OK! So far so good!

He taps one of the guys on the shoulder and explains about a mix up in the bill, and hands the guy the three dollars, then departs with his two-dollar tip in his pocket.

Now the fun begins!

Remember $30-$25=$5 Right? $5-$3=$2 Right?
So what’s the problem?
All is well, right?
Not quite. Answer this:
Each of the three guys originally gave $10.00.
They each got back $1.00 in change.
That means they paid $9.00 each, which times three is $27.00.
The delivery boy kept $2.00 for a tip.
$27.00 plus $2.00 equals $29.00.
Where the heck is the other dollar??????????

Photo by Ignacio Leonardi