I love the game set. :))
(a) How many cards are in a complete deck of Set?
3^4
(b) How many unique sets are there?
81*80/3/2 = 1080
(c) Find the number of sets where all three cards are the same for exactly 0 attributes.
Hm, this is where we seem to disagree.
I think you calculated the total number of 3 cards that wouldn't make a set.
If you are unfamilar with the game, a set can be made where all the attributes are all the same or all different.
For example, (1, red, oval hollow) (1, purple, diamond shaded) (1, green squiggle solid) would make a set because all the attributes are all different or all the same.
Nice job for question a and b. :))
Your solution with b was really clever.
=^._.^=