i finally revised everything in my made up question and see now that the discrepancy took place with Demorgan's and you are perfectly correct opening up avenues for updating one of the answer choices with your answer. Thank you Mike.
Indeed it's or/and boolean relationship which makes sense here and the double counting which you finely explain must be avoided between two subsets, could be 4!*4 too - yet you applied arrangements and showed symmetry applications there. Just perfect.
Indeed it's or/and boolean relationship which makes sense here and the double counting which you finely explain must be avoided between two subsets, could be 4!*4 too - yet you applied arrangements and showed symmetry applications there. Just perfect.
Success doesn't come overnight!
