BenB
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| posted on 18/11/06 at 11:18 PM |
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Maths #2
Explain this one.....
Three blokes go to a hotel to share a room. The manager says it will cost £30 so they each pay £10.
When they get to the room the manager realizes he's made a mistake and the room is £25.
He sends the £5 with the bellboy.
The men are keen to split the change equally so each take a pound and give the bellboy a £2 tip.
Each man paid £10 and got £1 back, so they've paid £9 each.
3 people @ £9 = £27.
Add the £2 tip.... £27+2=£29...
Where's the £1 gone?.........
It's a tricky one.....
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JoelP
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| posted on 18/11/06 at 11:19 PM |
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quote:
Originally posted by BenB
Each man paid £10 and got £1 back, so they've paid £9 each.
3 people @ £9 = £27.
Add the £2 tip.... £27+2=£29...
easy, they paid £27, of which £2 went to the bellboy and £25 to the hotel. £30 never came into it! 
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DIY Si
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| posted on 18/11/06 at 11:21 PM |
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What he ^^ said. You just need to be able to add it up right in the first place! 
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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Chippy
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| posted on 18/11/06 at 11:58 PM |
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Correct answer is they didn't pay £9 each, they paid £9.33.3333333r, and three times that equals £28, add the £2 tip, and heh! presto, theres
your £30. So gentlemen^^^ you are incorrect. Ray.
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DIY Si
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| posted on 19/11/06 at 12:03 AM |
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Must be scotsmen to cut a penny into 3!
“Let your plans be dark and as impenetratable as night, and when you move, fall like a thunderbolt.”
Sun Tzu, The Art of War
My new blog: http://spritecave.blogspot.co.uk/
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richardR1
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| posted on 19/11/06 at 02:10 AM |
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quote:
Originally posted by Chippy
Correct answer is they didn't pay £9 each, they paid £9.33.3333333r, and three times that equals £28, add the £2 tip, and heh! presto, theres
your £30. So gentlemen^^^ you are incorrect. Ray.
They did pay £9 each - of that £8.33.3333333r went to the hotel and £0.66.6666666r went to the bellboy.
MK Owners Club Member 1015
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BenB
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| posted on 19/11/06 at 01:50 PM |
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 Well done. Tis the correct answer....
They paid 25/3+2/3 each = 9. IE the £9 included the tip....
So the only maths is
(25/3+2/3+3/3)*3=30
Still confuses a hell of a lot of people....
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Liam
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| posted on 19/11/06 at 03:39 PM |
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quote:
Originally posted by BenB
Well done. Tis the correct answer....
They paid 25/3+2/3 each = 9. IE the £9 included the tip....
So the only maths is
(25/3+2/3+3/3)*3=30
Still confuses a hell of a lot of people....
No tricky maths required. The confusion comes from the loaded question "where's the £1 gone?" which tricks you into thinking that
what the three guys paid plus the tip ought to add up to £30, so you start looking at the maths puzzled. In fact that calculation is just a
meaningless statistic - as joelp says the 30 doesn't come into it.
Look at another example - what if the room went down to £20 and the bellboy came back with a tenner. Each bloke takes £3 (so has spent 7) and the
bellboy gets a £1 tip. So 3 x 7 = 21, plus the tip = 22. So where has the £8 gone? Answer - what £8? Why should this calc add up to £30?
Liam
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Mansfield
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| posted on 19/11/06 at 10:24 PM |
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To take Liam and Joel's point futher:
Explain this one.....
Three blokes go to a hotel to share a room. The manager says it will cost £30 so they each pay £10.
When they get to the room the manager realizes he's made a mistake and the room is £0.
He sends the £30 with the bellboy.
The men are delighted with this and each give the bellboy a £1 tip.
Each man paid £10 and got £9 back, so they've paid £1 each.
3 people @ £1 = £3.
Add the £3 tip.... £3+3=£6...
Where's the £24 gone?.........
It's a tricky one.....but I am a bit drunk!
[Edited on 19/11/06 by Mansfield]
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Mansfield
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| posted on 19/11/06 at 10:31 PM |
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Thinking about it, for £30 (or £25) a night wouldn't you rather have your own room.
Unless you were gay of course.
Gives a whole new meaning to 'bellboy' and 'receiving a tip'.
Wha sort of establishment was the hotellier running?
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JoelP
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| posted on 19/11/06 at 10:33 PM |
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That above, by mansfield, is actually an example (in a way) of what einstein used to do. he called them thought experiments, whereby you could test a
theory without actually doing it. By taking a situation to an exteme, it can make it completely obvious what the answer is.
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