Profile cover photo
Profile photo
Michael Piston
37 followers
37 followers
About
Posts

Post has attachment
C couldn't've told A that she was born in May because if so it would be possible that C told B 19, which would enable to determine she was born 5/19, since the 19th only occurs in May. Now that B knows that May is not an option, he concludes her birthdate is June 18 because she told him 18 and 18 appears only in June. Note that C couldn't've told B any other number because then he wouldn't've know that she didn't tell A May. For example, if she told him 14 then (as far as B knows) she might've told A July or August. 15 can be August or May.  16 can be July or May. 17 can be August or June. She can't have told him 19 because then he would have known immediately she was born May 19 even before A spoke.

Actually this was very simple quiz which took less than a minute to solve. I expected more of Singaporean High School Exams.

Post has attachment
Wait while more posts are being loaded