Maths/Logic Problem

[Future17]

I just read this story online and hoping someone can help:

http://www.msn.com/en-gb/news/world/how-to-fix-the-maths-problem-for-singapores-school-children-that-has-stumped-the-world/ar-AAaVZm2?ocid=mailsignoutmd

I'm totally confused because, as far as I can see, there's a step missing from the logic.

It says that Albert knows the month and Bernard knows the date, as they have been told the information "separately" and "respectively".

Albert says he doesn't know when the birthday is, but that he knows Bernard doesn't know either. Albert can only know Bernard doesn't know the birthday if it's not a unique date from the choice of 10. However, that only rules out May 19 and June 18 as there is more than one option for 14, 15, 16 and 17.

Anyone care to enlighten me? :confused:

[Future17]

Never mind, has been explained here: http://www.bbc.co.uk/news/world-asia-32297367

[easty]

I saw this earlier, and it took me about 20 mins to work it out.

Firstly. Albert doesn't know and knows from the outset that Bernard can't know. That must mean that the month Albert has been told can't be May or June. If it was then there was the possibility that Bernard would have known, had he been given the numbers 18 or 19. So you can rule out May and June.

Next, Bernard then says he knows, but because he only knows the date then you can rule out July 14th and August 14th. He can't have been told the number 14, or he wouldn't know the birthday date yet. So, if it's not the 14th, but Bernard definitely knows the answer, then it has to be July 16th.


EDIT - dammit.....I spent 10 mins writing this out, and now you already get it!