I sought help for this one so I am not going to spoil it for anybody. There are no tricks involved though just pure logic like said before:)

well boni - you may be right... as well as being my favourite time of day (so to speak), the dark, quiet hours have surely induced a certain level of madness and not infrequent fear and loneliness - but i've learned to embrace it (a vampiro heritage perhaps?)

you need to be bored to attampt the last puzzle, as it takes quite some patience (draw a table to work it out if you have a delayed plane trip or a long train journey to while away).

if you've been on here for a while, you notice patterns in peoples posting habits - some may have guessed by my increased visits recently that i've been seeking diversions from a work overload lol

*smug* i figured it out, literally as i was lying in bed, but sleep was escaping me. then i went to sleep easily. (the children's ages puzzle)

when thinking about it yesterday, i kept thinking about a different "problem", which i realize now is indeed no pure chance, as it is associated:

two children/teenagers meet. the first asks: "how old are you?" the second answers "i won't tell." the first: "well, when is your birthday?" (as in, what day of the year, not which year, obviously). the second: "hm, i won't tell you that either, because if i would, you would know how old i am." the first: "hmmm well tough for you, but now i know your birthday AND how old you are."

i "invented" that one by myself

well done 'smug'! so, are we supposed to work your puzzle out then? do you want to know how old child 1 is and when their birthday is? is it something like 'today' or maybe new year's day/eve? just wild guesses - i'll have to think (and are you sure we've got enough information to work it out...?)

well figure it out if you can! it's taken from real life!

unfortunately it's not 100% logic. in order to know the child's age, the other child has to be able to roughly judge if the child is, say, 3 or 13. to make it clearer (but still not 100% logic, unfortunately), we'd have to add this to the conversation:
beginning: it is today's date, i.e. 31st august 2007.
before the first child "knows":
the first: "well, so are you 3?" the second: "no". the first: "so, are you 15?" the second: "no". the first: "well, then you must be 11."

ok, so logically, the second could also be, say, 43 - but with common sense added to logic, anyone would be able to judge that this child can impossibly be 43, if you get what i mean.
but why?

now to einstein: it is the German who lives in the green house, the fourth, and who drinks coffee and smokes Prince who has fish.

this is a solution, i believe, which doesn't lead to any contradictions. but i'm not sure it's the only one as i resorted to some guess-work:
- when einstein says "the first house", does he mean the first from left?
- when he says that the green house is to the left of the white house, does he mean "immediately to the left"?
if you answer both those questions with yes, i think my solution is the only one. if not, i don't know, there might be more solutions.

I got a different answer, red house (last house) with brit drinking tea smoking blend looking after his fish!

I assumed green house (first) to the left was not immediately next to white (middle) as "next" was not used as in the other examples. This does not have any contradictions either!

I'm prob wrong tho - I'm never very good at these things!!

As for Einstein's puzzle (some people claim it is of Lewis Caroll's authorship):
it is the German who has fish.

As for the shani's puzzle - I suppose the other child was born on 29th February. However, there is still not enough information to guess the proper age - at least not without a quick glance at that kid

A good lead here would be if it is just some kid or a teenager. If it is the teenager, then there are only two possibilities: 13 and 17. But at this point it is still the dead end.

you're such a smartie, R! don't know how this will format, but...

house 1 2 3 4 5
color yellow blue red green white
nation norweigian dane brit german swede
drink water tea milk coffee beer
smoke dunhill blend pall mall prince bluemaster
pet cats horse birds fish dogs

anyone for any more?

that didn't go to plan - you'll have to space the rows out for yourselves!

u were right too shani (and part of only 2% apparently)! did it take u long?

r, yes, of course, you need a glance at the child (or the information in the first sentence that it is a child). i don't see how you get 13 and 17 though - in the range of up to 20-year-olds, in August 2007, the child could be 3, 11, 15, or 19. (not 7, because the year 2000 was not a leap year). as i said, it's not "pure" logic, unfortunately, but needs some "common sense"... now, normally, no-one would confuse a 11-year-old with a 19-year-old or older. so, if the first child excludes 15, and then knows, the second child would be 11, no? it's a bit like your problem - if the second child were 19, then excluding 15 would not be enough, 23 would also have to be excluded. but if knowing that the other is not 15 is enough to know what age the second child is, then it must be 11...

insomniac, well, making the table took me a moment as i did it on paper. but these kind of logic puzzles i find really easy - it's like it hasn't got too much to do with logic for me, but rather with patterns and symmetries. i got stuck though, and assumend that "to the left of" does mean "immediately to the left of" - only then i managed to continue.

here's another one:
a wizard has three students and after many years of study, wants to promote the cleverest of them to be his successor. they are all very clever, perhaps equally so, and so to determine who is really the brightest, he designs an examination.

yes?

they all sit in a triangle facing each other. each of them is given a hat on their head. they can all see the colour of the others' hats but not their own.
the wizard tells them:
i have five hats, three of them are white, two are black. of these five hats i have given each of you one, and hidden the rest. now the first of you who knows what colour your own hat is, wins the contest and will be my successor.

the three students sit there staring at each other, and after a short while, they all yell at the same time: "mine is white!"

they are all right. apparently, they are really equally smart and fast-thinking. but how did they find out?