Okay I'm taking a break for a moment to analyze a brain teaser.  This one was posted to the New York Times : Albert and Bernard just met Cheryl. “When’s your birthday?” Albert asked Cheryl.  Cheryl thought a second and said, “I’m not going to tell you, but I’ll give you some clues.” She wrote down a list of 10 dates: May 15 — May 16 — May 19 June 17 — June 18 July 14 — July 16 August 14 — August 15 — August 17 “My birthday is one of these,” she said. Then Cheryl whispered in Albert’s ear the month — and only the month — of her birthday. To Bernard, she whispered the day, and only the day. “Can you figure it out now?” she asked Albert.  Albert: I don’t know when your birthday is, but I know Bernard doesn’t know, either. Bernard: I didn’t know originally, but now I do. Albert: Well, now I know, too!  When is Cheryl’s birthday? Several Solutions have been posted here and here .  Unfortunately each has a flaw in its logic and is wrong. The analysis begi