Start with 2 identical decks and take all the diamonds out of one of them. Turn the diamonds into suns by adding 4 points with a red pen or marker. Shuffle them into a standard deck. They can always be separated into 2 standard decks later (if you can handle that the diamonds are a little different on one deck). Oh yeah, ask a question:

If you had a 5-suited deck (65 cards), what would the hand rankings be (including 5-of-a-kind)?

Same question with the 3-suited deck (39 cards).