The complement of A, representing baseball players younger than 9 years old, includes players who are 9 years old and older. In this specific case, there are 6 players in the complement of A, as there are 4 players aged 9 and 2 players aged 10.
The complement of the set A, denoted as A^c, includes all elements that are not in A. In this context, A represents baseball players younger than 9 years old. The age groups provided are 7, 8, 9, and 10 years old. Therefore, the complement of A includes players who are 9 years old and older.
Let's calculate the complement by summing the number of players in age groups 9 and 10:
Number of players in A^c = Number of players aged 9 + Number of players aged 10 = 4 + 2 = 6
So, there are 6 players in the complement of A, which means there are 6 players who are 9 years old or older.