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Little mathematical enigma...


Little mathematical enigma...

Three guys step into a hotel lobby and approach the front desk. One of them asks for a room for three.
They're told it costs £30 so they pay the money and head on up to the room.
Suddenly the woman at the front desk realises she's over charged them by £5. So she asks a bell boy to take the £5 up to the guys.
The bell boy takes the money and walks into the lift. Realising he can't split £5 between 3 people he decides to pocket £2 for himself and give £1 each to the three guys.

Now then, each guy originally paid £10 for the room for a total of £30. But the bell boy gave each of them £1 in return. So in fact they each paid £9 for the room, for a total of £27. The bell boy pocked £2 for himself, bringing the grand total to £29.
Where did the other £1 go? Tongue
Posts: 791
Registered: 04-08-2007

Little mathematical enigma...

Now I've seen this on a Forum somewhere B4.

Along with a concise mathamatical explanation ................... that I never really understood.

In laymans terms :-

I think it is something to do with the actual cost of the room being only £25 (NOT £30).

Therefore the three guys actually overpay (by £2) towards the cost of the room.
'Cos 3 x 9 = 27.

Therefore the switched on bell boy pockets the odd £2.

The number 30 don't really come into the equasion at all.

Little mathematical enigma...

The answer is, the math is incorrect.

At the start, it works on the presumption the room is £30, then moves on to state the room is only £25.

Only at the end, the math again works on the £30 presumtion and uses a little trickery to fool you (and all looks pretty plausable).

The answer is that indeed, each man pays £9, totaling £27. But you are meant to take the £2 away from this figure, to get the value of the room.

A simpler way of showing this, what if the full £5 refund is given, what is the total value of the room? This is the target, and not £30.