The head of the department told two professors (Alice and Bob) that one of them is one year older than the other but certainly both of them were born after 1949. Then one has heard the following dialogue:

A: I do not know what year you were born.
B: I do not know what year you were born either.
A: I do not know what year you were born either.
B: I do not know what year you were born either.
A: I do not know what year you were born either.
B: I do not know what year you were born either.
A: Now I know what year you were born.
B: Then I also know what year you were born.

How old are Alice and Bob? (You may assume that Alice and Bob know their own birthdays)

Mean Quest | Rating: 4.00
Posted on 2006-12-10 by Dennis (Solution Posted, 15 Comments)

Horoscope Hijinks II | Rating: 4.00
Posted on 2006-12-05 by Federico Kereki (Solution Posted, 4 Comments)

Crash Course | Rating: 4.14
Posted on 2006-12-01 by Gamer (No Solution Yet, 11 Comments)

Arbitrary Adventures Analysis | Rating: 4.00
Posted on 2006-11-20 by Old Original Oskar! (No Solution Yet, 10 Comments)

Button puzzle (2) | Rating: 4.50
Posted on 2006-10-27 by Tristan (Solution Posted, 11 Comments)

An Income And Expenditure Problem | Rating: 3.33
Posted on 2006-10-17 by K Sengupta (Solution Posted, 1 Comments)

Button puzzle | Rating: 4.00
Posted on 2006-10-13 by Tristan (Solution Posted, 7 Comments)

Another Time And Work Problem | Rating: 4.50
Posted on 2006-09-14 by K Sengupta (Solution Posted, 4 Comments)