Probability Formulas
Here are some basic probability formulas that are frequently used in quantitative aptitude exams, along with a table for quick reference:
Probability Formula |
Description |
|
P(A or B) = P(A) + P(B) – P(A and B) |
Probability of the union of two events |
|
P(A and B) = P(A) x P(B|A) = P(B) x P(A|B) |
Probability of the intersection of two events |
|
P(A|B) = P(A and B) / P(B) |
Conditional probability |
|
P(B|A) = P(A and B) / P(A) |
Conditional probability |
|
P(A’) = 1 – P(A) |
Probability of the complementary event |
|
P(A) + P(A’) = 1 |
Probability of the sample space |
|
P(A and B) = 0 if A and B are mutually exclusive events |
Probability of two mutually exclusive events |
|
P(A and B) = P(A) x P(B) if A and B are independent events |
Probability of two independent events |
|
P(A and B) > P(A) if A and B are dependent events |
Probability of two dependent events |
|
P(A) x P(B) ≤ P(A and B) ≤ min(P(A), P(B)) |
Inequality for the probability of intersection |
|
P(A or B or C) = P(A) + P(B) + P(C) – P(A and B) – P(A and C) – P(B and C) + P(A and B and C) |
Probability of the union of three events |
Note: P(A) represents the probability of event A. P(B|A) represents the probability of event B given that event A has occurred. P(A and B) represents the probability of both events A and B occurring.
Practice Quiz:
Probability – Aptitude Questions and Answers
Probability – Aptitude Questions and Answers: Are you preparing for a job interview or an entrance exam, or want to improve your quantitative skills? If so, then it is important to have a good understanding of probability and how it works. Probability is an integral part of mathematics and plays a crucial role in fields like science, engineering, finance, and economics.
In this article, we will discuss the most common probability question types commonly asked on quantitative aptitude tests. Whether preparing for a job interview, an entrance exam or simply looking to sharpen your quantitative skills, this article will help you gain a deeper understanding of probability and its applications in Quantitative Aptitude.