S={ 1,2,3,4,5......280}. Find the total number elements in set S divisible by 2,3,5 or 7.
If your question means "any one element that is divisible by 2, 3, 5, 7 at the same time, or divisible by all four", then there is only one such element:
210 mod [2, 3, 5, 7] = 0
If your question means "any one element that is divisible by ANY ONE of the four (2, 3, 5, 7), then All of them except 1 are divisible by at least one of the four, or 279 numbers.