Question

A fair die is thrown once . The probability for getting a composite number less than 5 is ​

Answer 1

Given: A fair die is thrown once.

We have to find the probability of getting a composite number less than$5$.

As we know that the formula to calculate the probability is:

$P(A)=\frac{\text { Number of Favourable Outcome }}{\text { Total Number of Favourable Outcomes }}$

$=>P(A)=\frac{n(A)}{n(S)}$

Where,

$P(A)$ is the probability of an event “A”.

$n(A)$ is the number of favorable outcomes.

$n(S)$is the total number of events in the sample space.

We are solving in the following way:​

We have,

A fair die is thrown once.

Therefore, sample space = {$1,2,3,4,5,6$}

$\therefore n(S)=6$

Event (A) = Getting a composite number less than$5$.

i.e (A) => {$4$}

$\therefore n(A)=1$

So, the probability of getting a composite number less than$5$ will be:

$=>P(A)=\frac{n(A)}{n(S)}$

$=>P(A)=\frac{1}{6}$

Hence, the probability of getting a composite number less than$5$ will be$\frac{1}{6} or 0.166$.

Answer 2

• As per the data given in the question, we have to find the value of the expression.

            Given data:- A fair die is thrown once.

            To find:- Value of the expression.

            Solution:-

• The formula of probability:-

           $\begin{array}{l}P(A)=\frac{\text { Number of Favourable Outcome }}{\text { Total Number of Favourable Outcomes }}\\ \\=>P(A)=\frac{n(A)}{n(S)}\end{array}$

         Where,

P(A) is the probability of an event “A”.  

n(A) is the number of favorable outcomes.  

n(S)is the total number of events in the sample space.

 We are solving in the following way:​  

 We have,  

 A fair die is thrown once.  

Therefore, sample space $=1,2,3,4,5,6$

      Therefore,

           $n(S)=6$

Event (A) = Getting a composite number less than$5$.

      $\begin{array}{l}\text { i.e }(\mathrm{A})=>\{4\} \\\therefore n(A)=1\end{array}$

So, the probability of getting a composite number less than $5$ will be:  

     $\begin{array}{l}=>P(A)=\frac{n(A)}{n(S)} \\=>P(A)=\frac{1}{6}=0.16.\end{array}$

           Hence we will get the probability $\frac{1}{6} \ or\ 0.16.$