Any ideas on these questions?

Assume that A×B={(e,2),(e,3),(e,6),(e,7),(b,2),(b,3),(b,6),(b,7)}.

(1) How many distinct elements are in A?
(2) How many distinct elements are in B?

Question

Any ideas on these questions?

Assume that  A×B={(e,2),(e,3),(e,6),(e,7),(b,2),(b,3),(b,6),(b,7)}.

(1) How many distinct elements are in A?  
(2) How many distinct elements are in B?

anonymous · Answer

This is the only other one stumping me:)

mathmate · Answer

Hint: 
Distinct elements of A are all those that are in the first position.  All elements of B are in the second position.

anonymous · Answer

e is only counted as one element right?

anonymous · Answer

e would be for A and b would be for B?

mathmate · Answer

Both e and b are in the first position (in different couplets), so they belong to A.

anonymous · Answer

Oh so is 2 for A and 4 for B?

mathmate · Answer

Exactly!

anonymous · Answer

Holy crap you are a genius
My other question I still cant quite get.....I have tried almost every answer and cannot get that multiple choice right.....It also is a 2 part question...
Thank you you have helped me out very much

mathmate · Answer

you're welcome!  :)