The probability of getting a king and a spade card when two cards are drawn simultaneously from a pack of 52 playing card is

Two cards are drawn from a pack of 52 playing cards one after the other. If $p_1$ is the probability of getting a queen in the first draw and a diamond card in the second draw when the first card drawn is replaced and $p_2$ is the probability of the same event when the first card drawn is not replaced. Then $\frac{p_1}{p_2}=$

Bag $A$ contains 4 white and 2 black balls, bag $B$ contains 3 white and 3 black balls and bag $C$ contains 2 white and 4 black balls. If a bag is chosen at random and a ball is chosen at random from it, then the probability that the ball drawn is black is

A random variable $X$ has the following probability distribution

$$ \begin{array}{llllllllll} \hline X=\mathbf{x}_i & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\ \hline P\left(X=\mathbf{x}_i\right) & 10 k & 9 k & 8 k & 8 k & 6 k & 5 k & 4 k & 3 k & k \\ \hline \end{array} $$

where $k$ is a real number.

If $A=\left\{x_i \mid x_i\right.$ is a prime number $\}$ and $B=\left\{x_i \mid x_i>5\right\}$ are two events, then $P(A \cup B)=$