3. Find the following cardinalities: (a) $|A|$ when $A=\{4,5,6, \ldots, 37\}$. (b) $|A|$ when $A=\{x \in \mathbb{Z}:-2 \leq x \leq 100\}$. (c) $A \cap Bl$ when $A=\{x\in \mathbb{N}: * \leq 20\}$ and $B=\{x \in \mathbb{N}: x$ is prime $\}$. S.P.PB.216