The answer to the second question: 3 (neither black nor the number 5, then the answer is that there are only three cards: red 3, red 7, red 10. )

The answer to the third question: 2 (neither red nor the number 7, only two cards are eligible: two black 5s).

Answer to the fourth question: 4 (red and the number is not 7, four are qualified: two red 5, red 3, red 10).

Here's how to do it.