This really is a mind bender!!

Three guys check into a hotel, asking for one room for the night. The hotel clerk says the bill is £30, so the guests split it evenly and pay £10 each.

Later the clerk realizes that he’s overcharged the guys and the bill should only be £25.

In order rectify this, he takes the £5 that is owed to the lads in order to bring the bill down to £25. On the way to the room, he realizes that he cannot divide £5 equally between three people.

As the guests are still unaware of the actual total of the revised bill, the clerk decides to just give each of the men £1 each and then keep the leftover £2 as a tip for himself.

So, each of them got £1 back: meaning they only paid £9 each; bringing the total paid to £27. The clerk has the leftover £2.

The £27 that guys paid, + the £2 the clerk kept = £29 so, if the guests originally handed over £30, what happened to the remaining £1?