The scene
Astronomy Classroom · Assembly tablesA school telescope’s lens disappeared during assembly. The recording shows someone placing it under their own table. Three tables stand in a line, and the chosen one was in the middle.
The names were erased from the plan, but two position comparisons remained. Each rules out one end and, together, they reconstruct the complete order.
What we know for certain
One of these people hid the lens under their own table, without help. There are exactly three tables in a line and one per person. Left and right always refer to the same plan viewed from the doorway. Nobody changed tables.
The three accounts
Hugo Vidal
Activity leader«My table was near the window.»
Ivet Costa
Student«I worked at the table I was assigned.»
Joel Serra
Assistant«I did not move any table during assembly.»
Examine the evidence
0 of 5 openedOpening these five clues does not cost points.
01The first relationship
Hugo’s table was to the right of Ivet’s. They are not stated to be adjacent.
02The second relationship
Joel’s table was to the right of Hugo’s. Both comparisons use the same direction.
03The recorded location
The lens is placed under the middle table: the one with a table on either side.
04The complete plan
Only those three tables existed, and none was outside the recording. The window alone does not establish left or right.
05The allocation
Each person worked and stored materials only under their own table. The lens did not move after it was hidden.