$A$ letter is chosen at random from the word $ASSASSINATION$. Find the probability that the letter is a vowel. (in $/13$)

$A$ die is thrown. Find the probability of the following event: $A$ number greater than or equal to $3$ will appear.

If $A$ and $B$ are two events,what is the probability that exactly one of them occurs?

When three coins are tossed simultaneously,what is the probability of getting a head on the first,a tail on the second,and a head on the third?

If $A$ and $B$ are events of a random experiment such that $P(A \cup B) = \frac{4}{5}$, $P(\bar{A} \cup \bar{B}) = \frac{7}{10}$, and $P(B) = \frac{2}{5}$, then $P(A)$ equals

Let $A$ and $B$ be two events such that $P(A') = 0.3$,$P(B) = 0.4$,and $P(A \cap B') = 0.5$. Then $P(A \cup B')$ is: