Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Probability Distributions

Question:

A biased die is such that probability of getting 2 is $\frac{1}{10}$ and other scores being equally likely. The die is tossed twice and X denotes number of 2 obtained. Which of the following are correct ?

(A) The possible values of X are 0, 1, 2, 3, 4.

(B) The possible values of X are 0, 1, 2.

(C) Probability of getting at least one 2 is 0.046.

(D) Probability of getting at least one 2 is 0.19.

(E) Mathematical expectation of X : E(X) = 0.18.

Choose the correct answer from the options given below :

Options:

(A) and (D) Only

(B) and (D) Only

(B) and (E) Only

(C) and (E) Only

Correct Answer:

(B) and (D) Only

Explanation:

The correct answer is Option (2) → (B) and (D) Only

(B) X represents the number of times a 2 appears in two tosses of the die.

$X=0$ (no 2's appear)

$X=1$ (one 2 appears)

$X=2$ (both are 2's)

X ∼ Binomial $(n=2,p=\frac{1}{10})$

(D) $E(X)=np=2×\frac{1}{10}=0.2≃0.18$