# Disk colour riddle

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Imagine a disk spinning like a record player turn table. Half of the disk is black and the other is white. Assume you have an unlimited number of colour sensors. How many sensors would you have to place around the disk to determine the direction the disk is spinning? Where would they be placed?

SherlockHolmes Expert Asked on 12th November 2018 in

You only need two and they should NOT be placed at opposite sides.

CugelTheWise Expert Answered on 12th November 2018.

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