The rotating gears

The rotating gears

The image shows four gears that are connected to each other. Gears A and D each have 60 teeth while gear B has 40 teeth and C only 20. When turning the system,

Which gear will spin faster, A or D?


Both will spin at exactly the same speed. The gears of equal measure rotate at the same speed regardless of the number and size of the gears between them.