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 : |
(A) and (D) Only (B) and (D) Only (B) and (E) Only (C) and (E) Only |
(B) and (D) Only |
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) $E(X)=np=2×\frac{1}{10}=0.2≃0.18$ |