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With any number of disks will always be 2 ways that this works. All the disks land on the red side or all the sides landing on the green side. The amount of possibilities will always be 2 to the power of the number of sides. For example with 1 disk the they would be the same 2/2^1 times or every time. With n disks the probability of all disks being the same color would be 2/2^n times or 1/2^(n-1).