Handshake Problem. Mr. and Mrs. Smith currently hosted the party at which 3 other couples attended. Several handshakes took place. No one shook hands with their respective own spouse, no one shook hands with same person twice, and obviously, no one shook his/her own hand.
After all handshakes were completed, Mr. Smith inquired every person, comprising his wife, how many hands he or she had shaken. To his surprise, every person gave the different answer. How many hands Mrs. Smith shook?