Aarav and Bhargav just become friends with Chaya, and they want to know when her birthday is. Chaya give them a list of 10 possible dates.
May 15 May 16 May 19
June 17 June 18
July 14 July 16
August 14 August 15 August 17
Chaya then tells Aarav and Bhargav separately the month and the day of her birthday respectively.
Aarav: I don't know when Chaya's birthday is, but i know that Bhargav does not know too
Bhargav: At first I don't know when Chaya's birthday is, but I know now.
Aarav: Then I also know when Chaya's birthday is.
So when is Chaya's birthday?