There are 5 couples attending a party. Everyone shakes hands with the people they don’t know. John asks everyone at the party, including his wife, how many hands they shook, and gets 9 different answers. How many hands did John’s wife shake?
Source: Paraphrased from ‘Art and Craft of Problem Solving’, by Paul Zeitz
Happy problem solving!
Feel free to email your solution to [email protected] or check the solutions page next week!
About the author
