← Curifold Puzzle School · 7 minutes ·
At the fictional reading room, a blue envelope is found on a desk. Mina entered at 9:05 and the envelope was seen at 9:10. It is tempting to connect these details into a story. Your task is to distinguish what the record says from what remains possible.
- Record: what is stated?
- Inference: what follows?
- Gap: what is unknown?
The idea
A fact in this puzzle is information explicitly supplied by its rules or records. A deduction follows without another assumption. A possibility may fit but is not established. Keep these categories separate. “After” is a time relationship; it does not identify who caused an event. In this fictional exercise we accept the stated records as accurate. Outside it, a record’s reliability may itself need checking.
Try it yourself
The clues
- These observations are accurate.
- The record does not list everyone who entered or left.
- Nobody recorded who placed the envelope.
| Time | Observation |
|---|---|
| 9:00 | The desk is empty. |
| 9:05 | Mina enters the room. |
| 9:10 | A blue envelope is on the desk. |
Hint 1
Underline only information actually stated.
Hint 2
Try two stories: Mina placed it, or someone else did. Do both fit?
Which conclusion follows?
Mina’s arrival fits that story but does not prove the action. Another person could have placed it.
The empty desk and later envelope establish this interval without identifying a person.
The entry record is explicitly incomplete, so an unlisted arrival remains possible.
Read all responses and explanations
Mina placed the envelope.
Mina’s arrival fits that story but does not prove the action. Another person could have placed it.
The envelope appeared after 9:00 and by 9:10.
The empty desk and later envelope establish this interval without identifying a person.
Nobody else entered.
The entry record is explicitly incomplete, so an unlisted arrival remains possible.
Which new observation directly addresses the missing fact?
This concerns the action we need to identify. The observation’s accuracy would still matter.
A colour preference does not establish an action or connect a person to this envelope.
The furniture count does not identify who put the envelope on the desk.
Read all responses and explanations
Someone is seen placing the envelope.
This concerns the action we need to identify. The observation’s accuracy would still matter.
Mina likes blue.
A colour preference does not establish an action or connect a person to this envelope.
There are four desks.
The furniture count does not identify who put the envelope on the desk.
Reveal the complete solution
The person is undetermined. Mina placing the envelope and someone else placing it both fit. The supported interval is after 9:00 and no later than 9:10.
Make it your own
Make columns for stated, follows, and unknown. Sort the first question’s answers into them. Write an observation that would remove the uncertainty without guessing anyone’s personality.
Your takeaway
- Copy an exact observation
- State the deduction it supports
- Give an alternative explanation
- Identify the missing evidence
No account required. Completion is saved only on this device. Answers and notes disappear when you leave or reload this page. The printable sheet is blank for your own notes.
Original fictional educational practice, separate from the puzzles sold in the books. Use the stated rules; there is no speed target or score.
Read the related journal guide · Continue exploring the lessons
Original educational content by Andrew Stinson Books, developed with AI assistance. Our editorial approach.