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 elements transform independently each frame: a central arrow rotates by a fixed angle (±45°) per step, while a small satellite circle advances one position per step around the four corners of the frame (TL→TR→BR→BL or reverse).
Explanation
This question belongs to the dual-speed rotation family, where two independent visual channels each follow their own rule simultaneously. Candidates who lock onto only one element will be misled: option A places the arrow correctly but the circle at the opposite (180°-away) corner — a classic 'wrong circle corner' trap. Option B reverses the arrow's rotation direction while keeping the circle correct, exploiting the symmetric look of a 45° counter-rotation. Option D skips the arrow two steps ahead instead of one, tempting candidates who miscounted frames. Option E repeats the state from the previous frame, catching anyone who failed to apply any progression at all. Only option C satisfies both constraints simultaneously — the arrow at the correct angle and the circle at the next sequential corner.
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
Related tags