# NCERT Class 12-Mathematics: Chapter – 13 Probability Part 16 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 54:

A die is tossed twice. A ‘success’ is getting an even number on a toss. Find the variance of the number of successes.

Let be the random variable for a ‘success’ for getting an even number on a toss

At

At

At

Thus,

And

Question 55:

There are cards numbered to , one number on one card. Two cards are drawn at random without replacement. Let denote the sum of the numbers on two cards drawn. Find the mean and variance of .

Here,

Let random variable be which denotes the sum of the numbers on two cards drawn.

At

At

At

At

At

At

Also,

## Objective Type Questions

### Choose the Correct Answer from the Given Four Options in Each of the Exercises from 56 to 82

Question 56:

If then is equal to

(A)

(B)

(C)

(D)

Question 57:

If equals

(A)

(B)

(C)

(D)

Question 58:

If and then equals

(A)

(B)

(C)

(D)