This set of Aptitude Questions and Answers (MCQs) focuses on “Probability”. These questions are beneficial for various competitive exams, placement interviews, and entrance tests.

1. Which of the following options is correct with respect to the probability of an event A?
a) P(A) > 1
b) P(A) < 0
c) 0 ≤ P(A) ≤ 1
d) P(A) = – 1

Explanation: 0 ≤ P(A) ≤ 1 is correct because the probability of any event is always between more than or equal to zero and less than or equal to one.

2. Which of the following options is incorrect with respect to an event A?
a) P (A) + P (A) = 1
b) 0 ≤ P (A) ≤ 1
c) P(ɸ) = 0
d) P(A) > 1

Explanation: P(A) > 1 is incorrect as the probability of an event can never exceed one, it can acquire a maximum value of one.

3. What are the events called which can never occur together according to the probability theory?
a) Collectively exclusive events
b) Mutually exclusive events
c) Mutually exhaustive events
d) Collectively exhaustive events

Explanation: Mutually exclusive events are things that can’t happen at the same time. For example, you can’t get head and tail at the same time while tossing a single coin.

4. What is the term used for all possible outcomes for a random experiment?
a) Event space
b) Sample space
c) Marginal space
d) Exclusive space

Explanation: As per the definition an event space contains all possible events for a given experiment or happening.

5. Which of the following terms explains the probability of an event irrespective of the outcome of another variable?
a) Cumulative probability
b) Conditional probability
c) Marginal probability
d) Individual probability

Explanation: Marginal probability is correct as Marginal probability is the term used to describe the probability of an event irrespective of the outcome of another variable.

6. What will be the marginal probability of dependent and independent events?
a) Zero
b) One
c) Different
d) Same

Explanation: Marginal probability is the probability of an event irrespective of the outcome of another variable. Thus, the marginal probability of dependent and independent events will be same.

7. What is the probability of non – occurrence of an event Q?
a) Complement of Q
b) Union of Q
c) Intersection of Q
d) Q > 1

Explanation: Considering an event Q the probability of non – occurrence of Q is complement of Q as both would sum up equal to one. Probability of Q + probability of non – occurrence of Q = 1. Thus, probability of non – occurrence of Q is known as complement of Q.

8. What will be the joint probability of two independent events M and N?
a) P(M) + P(N)
b) P(M) * P(N) + P(M * N)
c) P(M) * P(N)
d) P(M) + P(N) – P(M * N)

Explanation: Given,
Two independent events M and N.
Joint probability = P(M) * P(N).

9. Which of the following is a condition for binomial distribution in probability?
a) Must have at least 4 trials
b) Only two possible outcomes
c) Trials must be dependent
d) More two possible outcomes

Explanation: By definition the basic condition for binomial distribution in probability is that it must have only two possible outcomes. Thus, only two possible outcomes is the correct answer.

10. In which of the following events the rule of addition of probability is used?
a) Mutually exclusive events
b) Dependent events
c) Empirical events
d) Exhaustive events

Explanation: In the case of mutually exclusive events the use of addition of probability rule is allowed to calculate the probability of the events occurring together.

More Aptitude Questions and Answers on Probability:

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