I know this is really simple but indulge me ok. I found this permuation problem at
How many bytes (a string of exactly 8 bits) contain exactly 5 zeros?
Here's the solution given :-
In this example note that the order selection of the bits that are a zero does not matter. Hence the postions of the zeroes in the byte form a 5 combination of the set of 8 elements. Thus the answer is C(8,5)=56.
Is there an easier way of understanding this ? Shouldn't it be a permutation problem ?