A bag contains $3$ red and $5$ black balls and a second bag contains $6$ red and $4$ black balls. A ball is drawn from each bag. The probability that one is red and other is black, is
$\frac{3}{{20}}$
$\frac{{21}}{{40}}$
$\frac{3}{8}$
None of these
Three coins are tossed. Describe Two events which are mutually exclusive.
Three coins are tossed once. Find the probability of getting no head.
From a pack of $52$ cards two cards are drawn in succession one by one without replacement. The probability that both are aces is
A set $S$ contains $7$ elements. A non-empty subset $A$ of $S$ and an element $x$ of $S$ are chosen at random. Then the probability that $x \in A$ is
A die is thrown, find the probability of following events: A number greater than or equal to $3$ will appear.