Weekly Puzzle Solution: Erika’s choice

October 31, 2017

Welcome to GeniiOnline’s Weekly Puzzle, powered by Art of Play! We’ll bring you a new puzzle every Monday, then publish the solution on Tuesday. 

In case you missed it yesterday, here’s the puzzle. Now, on to the solution!

Erika is thinking of the 6 of spades. Both Natalie and Dave know what cards exist. When Natalie says that she knows that Dave doesn’t know the card she is passing on the info that the card is NOT hearts or clubs because the 8 of hearts and queen of clubs do not have duplicates of their values. The announcement that Dave now knows the card eliminates the value 4 because Dave would still have two valid choices of this value. This leaves 6 of Spades, 7 of diamonds, and jack of diamonds. Because Natalie is able to claim knowledge of the card we know the suit was not diamonds because Natalie would still not have enough information to choose between the 7 and jack. 6 of spades is the only remaining valid choice.

Come back next Monday for a new puzzle!