You may work either independently or up to groups of 3. Be prepared to share your answers in class on Wednesday.

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

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 doesn't know too.

Bernard: At first I don'tknow 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?

Devise a strategy/plan with your group to convince me when Cheryl's birthday is.