Two circular disks each have 10 0s and 10th 1s spaced equally around their edges in different orders. Show that the disks can always be superimposed on top of each other so that at least 10 positions have the same digit.

The superimposition is possible in a way such that at least 10 positions will have same digit.

Explanation:

The solution to this question is possible by using the pigeonhole principle. which is given as Suppose that n+1 (or more) objects are put into n boxes. Then some box contains at least two objects.

Thus Two circular disks each have 10 0s and 10th 1s spaced equally around their edges in different orders are  superimposed on top of each other so that at least 10 positions have the same digit.

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