Permutation & Swap
Elements exchange positions according to a fixed rule. No new elements — just rearrangement.
Understanding this pattern
Permutation patterns rearrange elements within a fixed grid. Edges swap, quadrants rotate, or elements cycle through a defined order. The total number of elements stays constant — what changes is their configuration. These are among the most difficult patterns because the rule affects relationships between elements, not individual properties.
Example Question
Pattern Rule
In each frame, the four symbols occupying the cells of a 2×2 grid rotate one position clockwise around the perimeter (TL→TR→BR→BL→TL), so after four frames every symbol returns to its starting cell.
Explanation
The correct answer C is the only option in which every symbol has advanced exactly one position clockwise around the perimeter relative to the preceding frame, which is the invariant rule of this edge-swap family. Distractors are crafted to exploit common errors: options that look plausible may apply the rotation to only two or three cells (partial swap), reverse the direction to counter-clockwise, or swap only the two top cells while leaving the bottom pair fixed — each violating the global, simultaneous, single-step clockwise cycle. Because the transformation is a permutation with a period of four, candidates who try to memorise absolute positions rather than track relative movement are especially vulnerable to choosing a partially correct distractor.
How to spot it
- Same elements present in every frame, but in different positions
- Pairs of elements seem to swap places systematically
- The overall "inventory" of shapes/colours stays constant
Common traps
- Trying to track individual elements instead of the swap rule
- Confusing which pair swaps — it may alternate between different pairs
- Assuming a simple rotation when the rule is a more complex permutation
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