NCERT Class 12-Mathematics: Chapter –13 Probability Part 16

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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)