Basic Probability question

Question

A cigarette company packs 1to 5 different slips, labelled a, b,c,d,e, respectively, with each pack it produces. Suppose that you buy 2 packs of cigarettes of this brand. What is a good sample space for the experiment whose outcome is the pair of slips you receive with the 2 packs?

Answer 1

Well as order doesn't matter just list all possible pairs

{ (a,a) (a,b) (a,c) (a,d) (a,e) (b,b) (b,c) (b,d) (b,e) (c,c) (c,d) (c,e) (d,d) (d,e) (e,e) }

As order doesnt matter (b,a) and (a,b) are the same outcome