Question

A die is thrown once. The probability of getting a prime number on
its top is
A)1/4
.B)1/3
C) 1/2
D) 1/6
Ans 1/4​

Answer 1

$\huge{\mathcal{\underline{\red{AnSWer}}}}$

Possible outcomes when a die is thrown = {1,2,3,4,5,6}

Number of possible outcomes once = 6

(i) Let E be the event of getting a prime number.

Prime numbers on the die are = {2,3,5}

Number of favourable outcomes = 3

No of total outcomes=6

$p(e) = \frac{favourable \: outcomes}{total \: outcomes} \\ p(e) = \frac{3}{6} = \frac{1}{2}$

i.e probability=1/2

so, option(C) is correct

more to know:

Probability is a measure of the likelihood of an event to occur. Many events cannot be predicted with total certainty. We can predict only the chance of an event to occur i.e. how likely they are to happen, using it. Probability can range in from 0 to 1, where 0 means the event to be an impossible one and 1 indicates a certain event. Probability for Class 10 is an important topic for the students which explains all the basic concepts of this topic. The probability of all the events in a sample space adds up to 1.

The probability formula is defined as the possibility of an event to happen is equal to the ratio of the number of favourable outcomes and the total number of outcomes.

Probability of event to happen P(E) = Number of favourable outcomes/Total Number of outcomes

Answer 2

Working out:

Before we start our solution, let's know the formula or the way to find the probability of an event.

$\boxed{ \sf{P(E) = \frac{No. \: of \: trials \: in \: which \: the \: event \: happens}{Total \: no. \: of \: trials} }}$

So, let's use this to find the probability of above event.

GiveN:

• A dice of 6 faces numbered from 1 to 6.

We have to find the probability of getting a prime number on the top face of the dice.

Solution:

The possible outcomes 1,2,3,4,5 and 6

Let E = the event of getting a prime number.

Then,

The outcomes favourable to E = 2,3 and 5

• Total number of favourable outcomes = 3
• Total number of outcomes = 6

Therefore, P(E) = 3/6 = 1/2

So, The correct answer is:

$\large{ \boxed{ \red{ \bf{ \frac{1}{2}(option \: c)}}}}$

Explore more:

• Probability is the mathematical study of uncertainty and certainty of an event.
• An action performed to determine the favourable outcomes is known as Experiment.
• An outcome of a trial is known as Elementary or a Simple event.
• Probability is derived from a Latin name known as probabilitas which is the measure of authority of witness in a legal case in Europe.

And we are done !!