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:

From a pack of $52$ cards,one card is drawn at random. The probability that it is either a king or a queen is:

$A$ person can hit a bird once in three attempts. If the person makes three attempts, what is the probability that the bird is hit (in $/27$)?

In an experiment of throwing three fair dice,the probability of getting a sum of $16$ is ..........

$P, Q$ and $R$ try to hit the same target one after the other. If their probabilities of hitting the target are $\frac{2}{3}, \frac{3}{5}, \frac{5}{7}$ respectively,then the probability that the target is hit by $P$ or $Q$ but not by $R$ is

Six faces of an unbiased die are numbered with $2, 3, 5, 7, 11$ and $13$. If two such dice are thrown, then the probability that the sum on the uppermost faces of the dice is an odd number is