The probability of an impossible event,i.e.,$P(\phi)$,is

$A$ box contains $10$ good articles and $6$ defective articles. One article is chosen at random. What is the probability that it is either good or defective?

Let $A$ and $B$ be two independent events of a random experiment. If the probability that both $A$ and $B$ occur is $\frac{1}{6}$ and the probability that neither of them occur is $\frac{1}{3}$,then the probability of occurrence of $A$ is

Two dice are tossed once. The probability of getting an even number on the first die or a total of $8$ is

Events $E$ and $F$ are such that $P(\text{not } E \text{ and not } F) = 0.25$. State whether $E$ and $F$ are mutually exclusive.

There are $3$ families,each having $1$ boy and $1$ girl. If one child is selected from each family,what are the elements of the event that only girls are selected?