$2$ dice are thrown. Find the probability of getting a sum less than $6$.

Let $0 < P(A) < 1$,$0 < P(B) < 1$ and $P(A \cup B) = P(A) + P(B) - P(A)P(B).$ Then

In a single throw of $2$ dice,what is the probability of getting a multiple of $2$ on one die and a multiple of $3$ on the other?

If $A$ and $B$ are two events such that $P(A) = \frac{3}{8}$,$P(B) = \frac{5}{8}$ and $P(A \cup B) = \frac{3}{4}$,then $P(A|B) = $

$A$ man is known to speak the truth $3$ out of $4$ times. He throws a die and reports that it is a six. The probability that it is actually a six,is

The probabilities that a student will receive an $A$, $B$, $C$, or $D$ grade are $0.30$, $0.38$, $0.22$, and $0.01$ respectively. What is the probability that the student will receive at least $B$ grade?