Shaky Story
A Coding Every Day logic puzzle to solve using careful reasoning, complementary information, and deductive thinking.
One gathering. Nine answers. One exact result.
Every detail matters. Use the possible handshake totals, the spouse restriction, and the fact that all nine reported answers are different to determine Stacy Smyth’s exact number.
What happened at the gathering?
Stacy and Sam Smyth were known for throwing a heck of a good party. At one of their wild gatherings, five couples were present (this included the Smyths, of course).
The attendees were cordial, and some even shook hands with other guests. Although we have no idea who shook hands with whom, we do know that no one shook hands with themselves and no one shook hands with his or her own spouse.
Given these facts, a guest might not shake anyone’s hand or might shake as many as eight other people’s hands.
At midnight, Sam Smyth gathered the crowd and asked the nine other people how many hands each of them had shaken. Much to Sam’s amazement, each person gave a different answer.
That is, someone didn’t shake any hands, someone else shook one hand, someone else shook two hands, someone else shook three hands, and so forth, down to the last person, who shook eight hands.
Given this outcome, determine the exact number of hands that Stacy Smyth shook.
Need a starting hint?
Organize the clues
- Start with the people who reported the highest and lowest totals.
- Ask what must be true about the person who shook eight hands.
- Consider which reported total could belong to that person’s spouse.
- Track which connections are forced or impossible.
- Look for totals that complement one another.
- Keep the five spouse pairs visible as you reason.