Gears

Track each change of direction and compare the tooth counts.

3 gears · one intermediate gear

Ready to start?

Start with gear A. Follow each contact and choose the last gear’s speed and direction.

Example

Input: 60 RPM · Counterclockwise
GearTeethSpeed · Direction
A1260 RPM
Counterclockwise
B24To find

How to play

All gears mesh on the outside and are viewed from the same side. Every contact reverses direction. Next speed = current speed × current tooth count ÷ next tooth count. RPM means revolutions per minute.

Each round has six questions and no time limit. Choosing an answer locks it. Review the steps, then move to the next question. Finish all six to save the round. Active time includes reviewing the steps, but does not count time when this page is hidden. Speed does not affect your score.

Use Tab to reach a control, then Enter or Space to choose it.

Original practice puzzles, not a standardized assessment.

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