Target Exam

CUET

Subject

-- Applied Mathematics - Section B2

Chapter

Question:

A random variable 'X' denotes the number of sixes obtained in three throws of a die, Then, the mean of the distribution is:-

Options:

$\frac{1}{3}$

$\frac{1}{2}$

$\frac{1}{8}$

$\frac{2}{3}$

Correct Answer:

$\frac{1}{2}$

Explanation:

The correct answer is Option (2) → $\frac{1}{2}$

Random variable $X$ = number of sixes in 3 throws of a die

Each throw: probability of six = $p = \frac{1}{6}$, probability of not six = $q = 1 - p = \frac{5}{6}$

Number of throws: $n = 3$

This is a binomial distribution: $X \sim B(n, p)$

Mean of binomial distribution: $\mu = n p$

Mean = $3 \cdot \frac{1}{6} = \frac{3}{6} = \frac{1}{2}$