Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Probability

Question:

If a random variable X has the following probability distribution:

X

0

1

2

3

P(X)

$K$

$\frac{K}{2}$

$\frac{K}{4}$

$\frac{K}{8}$

then,

Match List-I with List-II

List-I

List-II

(A) The value of K is

(I) 2/15

(B) $P(0 <X < 2)$ is

(II) 1/15

(C) $P(1 < X < 3)$ is

(III) 8/15

(D) $P(X > 2)$ is

(IV) 4/15

Choose the correct answer from the options given below:

Options:

(A)-(I), (B)-(II), (C)-(III), (D)-(IV)

(A)-(II), (B)-(III), (C)-(I), (D)-(IV)

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

(A)-(IV), (B)-(I), (C)-(III), (D)-(II)

Correct Answer:

(A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Explanation:

The correct answer is Option (3) → (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

List-I

List-II

(A) The value of K is

(III) 8/15

(B) $P(0 <X < 2)$ is

(IV) 4/15

(C) $P(1 < X < 3)$ is

(I) 2/15

(D) $P(X > 2)$ is

(II) 1/15

Given: Probability distribution of random variable $X$:

$X$ 0 1 2 3
$P(X)$ $K$ $\frac{K}{2}$ $\frac{K}{4}$ $\frac{K}{8}$

Total probability = 1:

$K + \frac{K}{2} + \frac{K}{4} + \frac{K}{8} = 1$

LCM = 8:

$\frac{8K + 4K + 2K + K}{8} = \frac{15K}{8} = 1$

$\Rightarrow K = \frac{8}{15}$


(A) The value of K ⟹ $\frac{8}{15}$

(B) $P(0 < X < 2)$ = $P(X = 1)$ = $\frac{K}{2} = \frac{8}{15} \cdot \frac{1}{2} = \frac{4}{15}$

(C) $P(1 < X < 3)$ = $P(X = 2)$ = $\frac{K}{4} = \frac{8}{15} \cdot \frac{1}{4} = \frac{2}{15}$

(D) $P(X > 2)$ = $P(X = 3)$ = $\frac{K}{8} = \frac{8}{15} \cdot \frac{1}{8} = \frac{1}{15}$