Probability
Probability is a key quantitative aptitude topic that measures the likelihood of an event occurring. It is widely used in competitive exams and logical reasoning problems.
Fundamental Principles
Probability
The likelihood of an event occurring, ranging from 0 to 1.
Favorable Outcomes
Number of desired outcomes.
Total Outcomes
Total possible outcomes.
Certain Event
An event that always occurs (Probability = 1).
Essential Formulation Tips
- Always identify total outcomes first.
- Use formula directly.
- Check if events are independent or dependent.
- Use complement rule when easier.
Shortcut Execution Techniques
- P(E) = Favorable / Total.
- Complement: P(not E) = 1 − P(E).
- Independent: P(A and B) = P(A) × P(B).
- Mutually exclusive: P(A or B) = P(A) + P(B).
Contextual Inquiries (FAQs)
Q: What is the easiest way to solve probability questions?
A:
Q: What is complement rule?
A:
Example Breakdown: Basic Probability
Basic concept.Total outcomes = 2 (H, T).
Favorable = 1 (H).
Probability = 1/2.
Final Answer: 1/2.
Example Breakdown: Dice Example
Common exam question.Total outcomes = 6.
Favorable = 1.
Probability = 1/6.
Final Answer: 1/6.
Example Breakdown: Complement Example
Important concept.P(head) = 1/2.
P(not head) = 1 − 1/2 = 1/2.
Final Answer: 1/2.
Probability Practice Questions
Solve important probability questions for banking, SSC, CMAT, and placement exams.
Q1. Probability of getting even number on a die?
Q2. Probability of drawing red card from deck?
Q3. Probability of getting tail in coin toss?