Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Probability

Question:

Let X denote the number of hours you play during a randomly selected day. The probability that X can values x has the following form, where c is some constant.

$P(X=x)= \begin{cases}0.1&, & \text { if } x=0 \\ c x&, & \text { if } x=1 \text { or } x=2 \\ c(5-x)&, & \text { if } x=3 \text { or } x=4 \\ 0&, & \text { otherwise }\end{cases}$

Match List-I with List-II:

List-I

List-II

 (A) c

 (I) 0.75

 (B) P(X ≤ 2)

 (II) 0.3

 (C) P(X = 2)

 (III) 0.55 

 (D) P(X ≥ 2) 

 (IV) 0.15 

Choose the correct answer from the options given below:

Options:

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

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

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

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

Correct Answer:

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

Explanation:

The correct answer is Option (2) → (A) - (IV), (B) - (III), (C) - (II), (D) - (I)

$∑P(X)=1$

$0.1+c+2c+c(5-3)+c(5-4)+0=1$

$0.1+3c+2c+c=1$

$6c=0.9⇒c=0.15$

(A) c → (IV) 0.15

(B) $P(X≤2)=0.1+c+2c=0.55$ (III)

(C) $P(X=2)=2c=0.30$ (II)

(D) $P(X≥2)=2c+c=0.75$ (I)