CALLING THE MATHEMATICAL MIGHT OF MUMSNET ! - Please explain this maths problem to us !

[NomDePlume]

Watching 'Help', this mathematical problem was given to a client to solve......


3 men are in a cafe. The bill arrives and it is £30 in total. Each man puts in £10. The waiter colects the money and takes it to the till. The manager sees the £30 and tells the waiter that he has overcharged the men, the bill should have been £25, he orders the waiter to take £5 back to them with an apology.

On his way back to the table it occurs to the waiter that the men do not know how much he has overcharged them so decides to give them £1 each (£3 in total) and pocket the other £2 for himself. He gives them the £3.

Each man put in £10 to cover the original £30 bill. Each of the 3 men was reimbursed £1, so in reality the men paid £9 each. £9 x 3 = £27. If the waiter only put £2 in his pocket, this totals £29, WHERE DID THAT £1 GO ????

HELPPPPPPPPPPPPPPPPPPPPP ! DH and I have been trying to bend our brains round it for about half an hour, to no avail

[RTKangaMummy]

I remember this was on here last year

[NomDePlume]

I must've missed it, been on MN for 2 years !

[lilsmum]

NDP, why!!!!! lol, i hate puzzles like this, going to be trying to work this out all night now

[RTKangaMummy]

But then it was a dumb blond waitress

[Gobbledigook]

This is soooooooo old!

[lilsmum]

right someone must know the answer, please!!!

[SenoraPostrophe]

the "other £1" didn't go anywhere because the sum isn't the right one. The bill was 25, so nothing does or should add up to £30. In reality, each man paid £9 = £27. The bill was only £25, but they paid the other £2 to the waiter. Does that make sense?

[JanH]

last time

(I can't do it myself!)

[Posey]

God knows!
If you still haven't got the answer in half an hour, I'll ask dh when he gets in from work.

[lilsmum]

oh yeah i get it now, god that a good trick of the mind!

[NomDePlume]

Not really no !

Sums for me were.....

Original bill - £30 / 3 = £10 each

Waiter takes money - £30. Is told it is wrong and to take £5 back - £30 - £25 = £5.

This leaves the till with £25 and the waiter with £5. Waiter pockets £2. £5 - £2 = £3

He shares the £3 with the other men. £3 / 3 = £1 each

If each man paid in £10 and got £1 back then they only paid £9 each. so... 3 x £9 = £27.

£27 + £2 the waiter pocketed = £29.

I still don't get it !!!!!

[NomDePlume]

ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh !

In the time it took me to post that mumbling nonsense, the link was posted.... The fog lifts....

[SenoraPostrophe]

why are you adding the £2 to the £27?

really it's £27 minus £2 = the £25 in the till. Since the men have change out of their £30 why should anything add up to £30?

[Potty1]

Just given this dh who's the other side of four pints of lager. He's struggling with it as we speak....... PMSL!!

[Aero]

brilliant - off to confuse dh with this one!