$A$ bag contains $3$ white and $2$ black balls and another bag contains $2$ white and $4$ black balls. $A$ bag is chosen at random and a ball is picked up from it. The probability of the ball being black is:

Two marbles are drawn in succession from a box containing $10$ red,$30$ white,$20$ blue and $15$ orange marbles,with replacement being made after each drawing. Then the probability,that the first drawn marble is red and the second drawn marble is white,is

Two events $A$ and $B$ will be independent if

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

If $A_1$ and $A_2$ are independent events and $P(A_1 \cup A_2) = 0.5$ and $P(A_1) = 0.2$,then $P(A_2) = $ . . . . . . .

$A$ pandemic has been spreading all over the world. The probabilities are $0.7$ that there will be a lockdown,$0.8$ that the pandemic is controlled in one month if there is a lockdown,and $0.3$ that it is controlled in one month if there is no lockdown. The probability that the pandemic will be controlled in one month is