Dual Speed
Two properties change simultaneously at different rates. One moves every frame, the other every two frames.
Understanding this pattern
Dual-speed is one of the hardest pattern families. Two independent transformations operate at different frequencies: one changes every step, the other every two or three steps. You must track both independently. Frame 3 and frame 5 may look similar, but only one rule has reset while the other has advanced.
Example Question
Pattern Rule
Two independent changes occur. The hollow circle moves clockwise by one corner in every panel: top-left → top-right → bottom-right → bottom-left → top-left, so it next moves to top-right. Simultaneously, the arrow rotates 45° counterclockwise in every panel: down → down-right → right → up-right → up, so it next points up-left. Therefore the next panel has a hollow circle at the top-right and an arrow pointing up-left.
Explanation
Option C is correct because it shows the hollow circle at the top-right and the arrow pointing up-left. Option A has the correct circle position but its arrow points up-right. Option B has an upward arrow and the circle at the top-left. Option C has an up-left arrow and the circle at the top-right. Option D has the circle at the top-right but its arrow points down-left. Option E has the correct up-left arrow direction but places the circle at the bottom-left.
How to spot it
- Some property changes every frame while another changes every other frame
- Two independent elements behave on different rhythms
- The sequence seems to have a period, but alternating frames break it
Common traps
- Tracking only the faster-changing element and ignoring the slower one
- Assuming both elements follow the same cycle length
- Getting confused when one cycle resets mid-sequence
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