If $A=\{x \mid x \in N, x$ is a prime number less than $12\}$ and $B=\{x \mid x \in N, x$ is a factor of 10$\}$, then $A \cap B=$ .............

If $A=\left(x \in R: x^2-5|x|+6=0\right\}$, then $n(A)=\ldots \ldots$