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:

Two numbers $a$ and $b$ are chosen at random from the set of first $30$ natural numbers. Then the probability that $a^2 - b^2$ is divisible by $3$ is (in $/87$)

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

$A$ pair of dice is thrown twice in succession. The probability of getting prime numbers on both the dice in the first throw and composite numbers on both the dice in the second throw is

If $A$,$B$,and $C$ are mutually exclusive and exhaustive events of a sample space $S$ such that $P(B) = \frac{3}{2} P(A)$ and $P(C) = \frac{1}{2} P(B)$,then $P(A) = $

If two dice are thrown together,then the probability that the sum of the numbers appearing on them is a prime number is: