Albert and Bernard have 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 day of her birthday respectively.( To clarify....Cheryl tells Albert the month in which her birthday falls, and she tells Bernard the day’s number. In other words, Albert is told either May, June, July or August. Bernard is told either 14, 15, 16, 17, 18 or 19.)

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

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

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

So....when is Cheryl celebrating her birthday?

(Question was originally asked in an exam for ten year olds in the Singaporean education system).

Original source:https://www.facebook.com/kennethjianwenz/photos/a.173663129479243.1073741827.167504136761809/385751114937109/?type=1

On 18

I don't no where to start from.

July 16, should I explain or still leave it for others to figure out?

June 18

This is interesting. . . . .

July 16

July 16.

July 16

I also saw the explanation on BBC news and I really don't get the mathematician's basis for eliminating May and June, so all those above me forming nerd pls explain!

Lol, no Nerd Forming bro, the statement Albert made- "I know Bernard doesn't know too" simply means 'the month cheryl told me is different from the months that have the unique, unduplicated days 18, 19 so I'm sure Bernard does not know because no matter the day Bernard is told there will be more than one instance of that day' I hope you get it?