Who Ate My Cake?
Eileen bought a cake, and she put it on a table and left. There were four persons around, Andy, Brian, Calvin and Danny. One of them ate the cake while the others saw him eating it. When Eileen returned and saw the cake was missing, she asked who ate the cake and the replies were as follows:
Andy: Brian ate the cake.
Brian: Andy didn't eat the cake.
Calvin: Andy ate the cake.
Danny: Either Andy or Brian ate the cake.
If we know that exactly two of them were lying, then who ate the cake?