Which playing card replaces the question mark?

In a playing-card grid puzzle, cards are assigned point values under a standard convention: numbered cards (2 to 10) count as their face value, an Ace counts as 1, and every court card — Jack, Queen, King — counts as 10, regardless of suit. When cards are grouped into rows or columns, the pattern to test is whether every fully-visible group shares one constant total; once that total is confirmed, the missing card in an incomplete group can be found by subtracting the known cards from it.

1. Column 1: 4 + King (10) + 7 = 21

2. Column 2: 9 + 2 + 10 = 21

3. Column 3: 7 + 8 + 6 = 21

4. Column 4: Queen (10) + King (10) + Ace (1) = 21

5. Column 5: 3 + 10 + 8 = 21

6. Column 6 (with the missing card): 5 + 9 + ? = 21, so ? = 21 − 5 − 9 = 7

Every one of the five fully-visible columns totals exactly 21, so the same constant must hold for the sixth column. Substituting 7 back in gives 5 + 9 + 7 = 21, confirming the missing card's value is 7 (any suit).