If $P(A_1 \cup A_2) = 1 - P(A_1^c) P(A_2^c)$,where $c$ stands for complement,then the events $A_1$ and $A_2$ are

An urn contains $4$ red and $5$ white balls. Two balls are drawn one after the other without replacement,then the probability that both the balls are red is

An urn contains $10$ black and $5$ white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black?

For independent events $A$ and $B$,$P(A) = \frac{1}{3}$,$P(A \cup B) = \frac{2}{5}$,and $P(B) = p$. Find the value of $p$.

$A$ purse contains $4$ copper coins and $3$ silver coins. $A$ second purse contains $6$ copper coins and $4$ silver coins. $A$ purse is chosen randomly and a coin is taken out of it. What is the probability that it is a copper coin?

If $A$ and $B$ are two independent events and $P(A)=\frac{3}{5}$ and $P(B)=\frac{2}{3}$,then $P(A' \cap B')=$