← Curifold Puzzle School · 7 minutes ·
One of four fictional volunteers returned a brass token. The returner is the only person matching every clue. The candidate log is complete and accurate for this puzzle. Check the whole record rather than choosing the first partial match.
- Candidate: the whole record
- Conditions: check every one
- Decision: keep only full matches
The idea
Use one row per candidate and one column per condition. A single contradiction eliminates a candidate even when other details fit. A survivor is the answer only after all clues have been checked and the candidate list is known to be complete. Real records may need further scrutiny; this exercise states its reliability assumptions explicitly.
Try it yourself
The clues
- The returner arrived before 4:15.
- The returner used the east door.
- The returner did not carry a box.
- Exactly one listed person returned the token.
| Person | Arrival | Door | Box? |
|---|---|---|---|
| Ari | 4:05 | East | Yes |
| Bo | 4:10 | West | No |
| Cleo | 4:20 | East | No |
| Dev | 4:12 | East | No |
Hint 1
Check the time cutoff first.
Hint 2
Ari fails the box clue and Bo the door clue. Which remaining person passes the time test?
Who matches every clue?
Ari matches time and door but fails the no-box clue.
Cleo matches door and no box but arrives after the cutoff.
Dev passes all conditions. Bo, the fourth candidate, fails the east-door clue.
Read all responses and explanations
Ari
Ari matches time and door but fails the no-box clue.
Cleo
Cleo matches door and no box but arrives after the cutoff.
Dev
Dev passes all conditions. Bo, the fourth candidate, fails the east-door clue.
Why reject Ari?
List order has no stated meaning; use the actual conditions.
A single failed condition is enough when every clue must hold.
Trustworthiness is not supplied and cannot replace a clue check.
Read all responses and explanations
Names listed first are usually tricks.
List order has no stated meaning; use the actual conditions.
The box contradicts an explicit clue.
A single failed condition is enough when every clue must hold.
Dev sounds more trustworthy.
Trustworthiness is not supplied and cannot replace a clue check.
Reveal the complete solution
Dev alone fits. Ari fails no-box; Bo fails east-door; Cleo fails before-4:15. Dev passes all three conditions. Every rejection has an explicit reason.
Make it your own
Write a rejection reason for each other name. Then change the cutoff to 4:25. Cleo and Dev both survive: explain why a plausible answer would no longer be unique.
Your takeaway
- Copy the conditions
- Check every candidate against all conditions
- Name each contradiction
- Verify the survivor
- Test the changed cutoff
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Original fictional educational practice, separate from the puzzles sold in the books. Use the stated rules; there is no speed target or score.
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Original educational content by Andrew Stinson Books, developed with AI assistance. Our editorial approach.