1. **Problem statement:** Given the set $A = \{\{1, 2, 3\}, \{4, 5\}, \{6, 7, 8\}\}$, we need to: (a) List the elements of $A$. (b) Find $n(A)$, the number of elements in $A$. 2. **Understanding the problem:** The set $A$ is a set of sets. Each element of $A$ is itself a set. 3. **Listing the elements:** The elements of $A$ are exactly the sets inside it: $$\{1, 2, 3\}, \{4, 5\}, \{6, 7, 8\}$$ 4. **Finding $n(A)$:** The number of elements in $A$ is the count of these sets. There are 3 sets inside $A$. Therefore, $$n(A) = 3$$ **Final answer:** (a) The elements of $A$ are $\{1, 2, 3\}$, $\{4, 5\}$, and $\{6, 7, 8\}$. (b) $n(A) = 3$.