Three people go out for a meal and it comes to Â£30. They split the cost and pay Â£10 each. The waiter takes the money to the till and realises thet theres a special offer on and they only have to pay Â£25. So he put Â£25 pound in the till and goes to take Â£5 back to them, on the way is decieds to keep Â£2 for himself and gives Â£1 back to the customers. Now they have only paid Â£9 each for a meal.
So if you add the money up it goes like this: 9+9+9=27 add the money the waiter took +2=29. So wheres the other Â£1 gone??
Its a trick because the Â£1 hasent vannished its just the way you work it out. If you do it in reverse like so you will get Â£30: Â£30-Â£5=Â£25 thats the money for the meal. The Waiter keeps a pound and gives three back. So Â£25+1+1+1+2=30