The scene
Inventions Archive · Number panelA display case’s code was altered. Three technicians could each edit one column. The original code was lost, but two checks calculated before the change survived.
Comparing both checks with the current panel locates the edit.
What we know for certain
One of these people changed one digit in their own column. The other two digits stayed the same. Nobody exchanged permissions or made other changes. The original checks are exact, and allowed digits range from zero to nine.
The three accounts
Wanda Puig
Technician«I could only edit the third column.»
Xavi Prat
Programmer«My permission covered the first.»
Yuna Sol
Archivist«I controlled the second column.»
Examine the evidence
0 of 5 openedOpening these five clues does not cost points.
01The current panel
From left to right, the current digits are 4, 5 and 8. This corresponds to the first, second and third columns.
02The first check
Before the change, the ordinary sum of the three digits was 14.
03The second check
Before the change, the first plus twice the second plus three times the third gave 29. That is the complete calculation rule.
04Exclusive permissions
Wanda could edit the third column; Xavi, the first; Yuna, the second. Each permission remained unchanged.
05A single edit
One digit was increased in one edit. Both checks describe exactly the state before that edit.