Two cards are drawn one by one at random from a pack of $52$ cards. The probability that both of them are king, is
$\frac{2}{{13}}$
$\frac{1}{{169}}$
$\frac{1}{{221}}$
$\frac{{30}}{{221}}$
A fair coin is tossed repeatedly. If tail appears on first four tosses then the probability of head appearing on fifth toss equals
A die is thrown. Describe the following events : $A$ : a number less than $7.$ Find the $A \cup B$.
The probability of happening an event $A$ in one trial is $0.4$. The probability that the event $A$ happens at least once in three independent trials is
Two dice are thrown. The events $A, B$ and $C$ are as follows:
$A:$ getting an even number on the first die.
$B:$ getting an odd number on the first die.
$C:$ getting the sum of the numbers on the dice $\leq 5$
Describe the events not $B$
An experiment consists of recording boy-girl composition of families with $2$ children. What is the sample space if we are interested in knowing whether it is a boy or girl in the order of their births ?