Math Is Fun Forum

I apoligise as I'm not certain how to put this in latex fully but I'm pretty sure you can use some imagination with the square root.. ^^

What did the mathematician say after christmas lunch.....?

Fixed the LaTeX for you

A town has only one male barber. If he shaves every man in the town except for those who shave themselves, does he shave himself?

I have heard of a book that supposedly 'changed the world' called 'Principia Mathematica' by Sir Issac Newton (est. 1687).
Does anyone know where i could find some more information about it and possibly even give a web address?

There are three men on a train. One of them is an economist, one is a logician and one of them is a mathematician. They have just crossed the border into Scotland and they see a brown cow standing in a field from the window of the train standing parallel to where they're sitting.
The economist says, 'Look the cows in Scotland are brown'
The logician says, 'No. There are cows in Scotland of which one, at least is brown.'
And the mathematician says, 'No. There is at least one cow in Scotland, of which one side appears to be brown.'

I'm new to the forums, i'm 14 and in year 9 at St.Ives Secondary School, Cornwall, England
I have a keen interest in maths, science and english
I study maths and science at a gsce level at home because ive already basically mastered all of the year 9, 10 and 11 syllabus.
My dream in life is to become a doctor and maybe even go on to become a consultant

Hi, im a 14 year old boy from Cornwall and i need help solving the: 'Who owns the fish?' logic puzzle and i hope you take the time to read my situation and try as hard as you can to help.

Here is the link to said puzzle: http://www.mathsisfun.com/logicpuzzle.html

Let's say the houses are laid out like so: 1 2 3 4 5, one being on the far left of the row and five being on the far right of the row.

Here's what i've come up with so far...

1. The Noweigan lives in the first house and lives next to the blue house, so since there is no house to the left of number 1, number 2 must be blue.

2. The green house is on the left to the white one, so green can't be number 1, 2 or 5 because if it were 1, that would mean white would be 2 when in fact 2 is blue. It can't be 2 because, once again 2 is blue and it cant be 5 because it has nothing to the right of it.

3. Subsequently white can't be 1, 2, or 3 because number 1 has nothing to left of it. It can't be number 2 because it's blue and it can't be number 3 because that would mean number 2 is green when it is in fact blue.

4. This means number 4 is green because, as mentioned earlier it can't be 5 and therefore number 5 must be white.

5. This leaves me with the following discoveries; 1 and 3 must be be red and yellow or vise versa, the owner of number 4 drinks coffee because the house is green, the Brit lives in either 1 or 3 because he lives in a red house, the hockey player is in number 1 or 3 because the owner of the yellow house plays hockey, the horse owner lives in number 2 or 4 because the man who keeps horses lives next to the one who plays hockey.

thanks in advance,
Ash Jones