If $C$ and $D$ are two events such that $P(D) \neq 0$,then which of the following statements is correct?

From a lot containing $n$ good and $m$ bad articles, if $2$ articles are picked at random in succession without replacement, then the probability that the second article picked is bad is

$A$ coin is tossed three times. If event $E$ represents getting at least two heads and event $F$ represents getting a head on the first toss,find $P(E|F)$.

Two events $E$ and $F$ are independent. If $P(E) = \frac{3}{5}$ and $P(F) = \frac{3}{10}$, then $P(E'/F) + P(F'/E) = \text{ . . . . . . }$

$A$ box contains $10$ mangoes, out of which $4$ are spoiled. $2$ mangoes are taken together at random. If one of them is found to be good, then the probability that the other is also good is:

If $2 P(A) = P(B) = \frac{5}{13}$ and $P(A \mid B) = \frac{2}{5}$,then $P(A \cup B) = $ . . . . . . .