Probability - Aptitude MCQ Questions and Solutions with Explanations

61

Which of the following is not an example of a discrete probability distribution?

A) The number of bathrooms in a house B) The sale or purchase price of a house C) The number of bedrooms in a house D) Whether or not a home has a swimming pool in it

Discuss

Answer & Solution

Answer: Option B

Solution:

The sale or purchase price of a house

62

The collection of one or more outcomes from an experiment is called

A) Event B) Z-Value C) Probability D) Random Variable

Discuss

Answer & Solution

Answer: Option A

Solution:

An event is collection of one or more outcomes from an experiment.

63

The probability of success changes from trial to trial in

A) Sampling distribution B) Binomial distribution C) Hypergeometric distribution D) Geometric distribution

Discuss

Answer & Solution

Answer: Option C

Solution:

Hypergeometric distribution

64

Successive trials in binomial distribution are

A) Dependent B) Independent C) Equally Likely D) Mutually exclusive

Discuss

Answer & Solution

Answer: Option B

Solution:

Independent

65

Two dice are thrown simultaneously ,what is the probability of getting a total of 7?

A) $$\frac{{1}}{{3}}$$ B) $$\frac{{1}}{{6}}$$ C) $$\frac{{1}}{{12}}$$ D) $$\frac{{1}}{{24}}$$

Discuss

Answer & Solution

Answer: Option B

Solution:

n(S) = 6 × 6 = 36
E = {(1, 6), (6, 1), (5, 2), (2, 5), (4, 3), (3, 4)}
n(E) = 6
P(E) = $$\frac{{6}}{{36}}$$ = $$\frac{{1}}{{6}}$$

66

The mean of binomial distribution is

A) npq B) np C) $$\sqrt {{\text{npq}}} $$ D) $$\sqrt {{\text{np}}} $$

Discuss

Answer & Solution

Answer: Option B

Solution:

The mean of binomial distribution is "np"

67

Each trial in Binomial distribution has

A) One Outcome B) Two Outcome C) Three Outcome D) Four Outcome

Discuss

Answer & Solution

Answer: Option B

Solution:

Two Outcome

68

A bag contains 6 white and 4 black balls. Two balls are drawn at random. Find the probability that they are of same colour.

A) 1 B) $$\frac{{2}}{{15}}$$ C) 3 D) $$\frac{{7}}{{15}}$$

Discuss

Answer & Solution

Answer: Option D

Solution:

Number of ways two balls can be drawn from 10 balls (6 white +4 blacks)
$$ = {}^{10}{C_2} = \frac{{10 \times 9}}{{2 \times 1}} = 45$$
n(E) = Number of ways of drawing 2 balls from 6 white balls or 2 balls from 4 black balls
$$\eqalign{ & = {}^6{C_2} + {}^4{C_2} = 21 \cr & {\text{P}}\left( {\text{E}} \right) = \frac{{21}}{{45}} = \frac{7}{{15}} \cr} $$

69

In a Poisson probability distribution

A) It always contains a contingency table B) The number of trials is always less than 5 C) The probability of success is always greater than 5 D) The mean and variance of the distribution are same (equal)

Discuss

Answer & Solution

Answer: Option D

Solution:

The mean and variance of the distribution are same (equal)

70

The special rule of multiplication of probability, the events must be

A) Empirical B) Bayesian C) Independent D) None of These

Discuss

Answer & Solution

Answer: Option C

Solution:

If two events are independent, i.e. are not related, the special rule of multiplication is used to find the probability of their joint occurrence.
P(A and B) = P(A) × P(B)