Cheryl's Birthday

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tiffinboys
Posts: 8022
Joined: Fri Nov 11, 2011 11:00 pm
Location: Surrey

Cheryl's Birthday

Post by tiffinboys »

This logic question has been baffling the world.

http://www.bbc.co.uk/news/world-asia-32304126" onclick="window.open(this.href);return false;

Do you think that answer could have been some other date?
Catseye
Posts: 1824
Joined: Wed Oct 29, 2014 6:03 pm
Location: Cheshire

Re: Cheryl's Birthday

Post by Catseye »

Here is the question:

Albert and Bernard just become friends with Cheryl, and they want to know when her birthday is.

Cheryl gives them a list of possible dates.

May 15 May 16 May 19

June 17 June 18

July 14 July 16

August 14 August 15 August 17

Cheryl then tells Albert and Bernard separately the month and the day of her birthday respectively.

Albert: I don't know when Cheryl's birthday is, but I know that Bernard does not know too.

Bernard: At first I don't know when Cheryl's birthday is, but I know now.

Albert: Then I also know when Cheryl's birthday is.

So when is Cheryl's birthday?

and yes I can, (I've seen the solution in the telegraph :wink: ) I'm usually quite good at logic problems , but it had me stumped , I've seen easier problems in STEP test by Cambridge Uni in the compulsory question set for prospective computer science applicants :o

for 15 yr olds? pull the other one!
doodles
Posts: 8300
Joined: Tue Oct 27, 2009 9:19 pm

Re: Cheryl's Birthday

Post by doodles »

Discussing this on Radio 4's Today programme now and in an hour, so about 8.20 am
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