Let

$A = \{ z \in \mathbb{C} : |z - 2| \leq 4 \}$ and

$B = \{ z \in \mathbb{C} : |z - 2| + |z + 2| = 5 \}$.

Then the max $\{|z_1 - z_2| : z_1 \in A \text{ and } z_2 \in B \}$ is :

Let $z$ be a complex number such that $|z-6|=5$ and $|z+2-6 i|=5$. Then the value of $z^3+3 z^2-15 z+141$ is equal to :

Let $\mathrm{S}=\left\{z \in \mathbb{C}:\left|\frac{z-6 i}{z-2 i}\right|=1\right.$ and $\left.\left|\frac{z-8+2 i}{z+2 i}\right|=\frac{3}{5}\right\}$.

Then $\sum\limits_{z \in \mathrm{~s}}|z|^2$ is equal to :