Linear Arrangements — Revision Notes

⚡ 30-Second Revision

Fix slots and facing direction first.
Immediate = adjacent; second left = two-position offset.
“Somewhere left” does not fix a gap.
One valid layout proves possibility, not necessity.
Check negative clues before accepting the answer.

2-Minute Revision

Represent strong clues as fixed positions or blocks, then branch only where needed. Keep the observer's slot numbering separate from a person's left/right. Several arrangements can share a necessary answer. Conversely, a complete-looking arrangement can be invalid if it violates one exclusion. Finish by checking each clue and the requested perspective.

5-Minute Revision

Use slots 1–5 from left to right. For a person facing south in slot 2, “second to the left” points to slot 4, because that person's left is the observer's right. Now place B in 1, E in 5 and an A-C-D consecutive block in the remaining slots, all facing north: B-A-C-D-E. Explain why changing the facing direction changes relational translation but does not renumber the slots.

Vyyuha Quick Recall

S-F-C: Slots, Facing, Constraints. Then test the answer against every supplied condition.