Problem of the Month
Hint for Problem 5: SET!

1. Three of the six sets consist entirely of red cards.

2. First count the red cards with solid squiggles. Then count all the red cards with squiggles. Then count all the red cards.

3. Choose any two SET! cards. How many other cards go with those two to form a set?

4. See the previous hint.

5. Try encoding the cards as \(4\)-tuples \((p,q,r,s)\), where each coordinate represents a property, and each entry in each coordinate can be either \(1\), \(2\), or \(3\) corresponding to the three different options for each property. Can you identify when three \(4\)-tuples correspond to cards that form a set?