Class 12 RS Aggarwal Chapter-29 Probability Solutions - Free PDF Download
FAQs on RS Aggarwal Class 12 Solutions Chapter-29 Probability
1. What are the major topics covered in the RS Aggarwal Solutions for Class 12 Maths Chapter 29, Probability?
The solutions for this chapter provide detailed, step-by-step methods for key concepts aligned with the CBSE 2025–26 syllabus. You will find extensive practice on:
- Conditional Probability: Calculating the probability of an event when another event has already occurred.
- Multiplication Theorem on Probability: Finding the probability of the intersection of two or more events.
- Independent Events: Solving problems where the occurrence of one event does not affect the other.
- Bayes' Theorem: Applying reverse probability to determine the probability of an earlier event given a later event has occurred.
- Probability Distribution of a Random Variable: Tabulating the probabilities for each possible outcome of a random variable.
2. How do the RS Aggarwal solutions for Class 12 Probability improve board exam preparation?
These solutions are designed to build problem-solving skills for the board exams. They help by:
- Providing Variety: Offering a wide range of questions beyond the NCERT textbook, which prepares you for different problem formats.
- Clarifying Methods: Presenting clear, step-by-step answers that help you understand the correct method to use for each type of question.
- Reinforcing Concepts: By working through numerous solved examples, you can solidify your understanding of complex topics like Bayes' theorem and conditional probability.
- Building Confidence: Successfully solving the variety of problems in RS Aggarwal boosts your confidence for tackling any question in the final exam.
3. How do you solve a problem on dependent events, such as drawing two balls without replacement?
To solve such problems, you apply the Multiplication Theorem of Probability for dependent events. Let's take an example: A bag has 5 yellow and 7 blue balls. Two balls are drawn one by one without replacement. What is the probability that the first is yellow and the second is blue?
- Step 1: Find the probability of the first event. The probability of drawing a yellow ball first is P(Y) = 5/12.
- Step 2: Find the probability of the second event, given the first has occurred. Since the first ball was not replaced, there are now only 11 balls left. The probability of drawing a blue ball second is P(B|Y) = 7/11.
- Step 3: Apply the multiplication theorem. The required probability is P(Y and B) = P(Y) × P(B|Y).
- Step 4: Calculate the final answer. (5/12) × (7/11) = 35/132.
4. What is the difference in approach between solving a problem using the theorem of total probability and Bayes' theorem?
Both theorems are crucial, but they answer different types of questions. The Theorem of Total Probability is used to find the probability of an event by considering all possible scenarios that could lead to it. It calculates a 'forward' probability, like finding the overall chance of selecting a defective item from a factory with multiple machines. In contrast, Bayes' Theorem finds a 'reverse' conditional probability. If you already know an item is defective, Bayes' theorem helps calculate the probability it came from a specific machine.
5. Why is it a bad idea to skip RS Aggarwal's Chapter 29 on Probability for the Class 12 exams?
Skipping this chapter is not recommended. Probability is a high-weightage unit in the CBSE Class 12 Maths board exam, typically accounting for around 8 marks. The questions in RS Aggarwal cover all essential concepts and problem variations that are frequently asked. Mastering this chapter through these solutions ensures you are prepared for a significant portion of the exam paper and do not lose crucial marks.
6. What is a common mistake when finding the probability distribution of a random variable?
A common mistake is incorrectly defining the values the random variable (X) can take, or miscalculating the probability for each value. Another frequent error is failing to verify that the sum of all probabilities in the distribution equals exactly 1. For example, when tossing two coins, if X is the number of heads, X can take values 0, 1, or 2. You must calculate P(X=0), P(X=1), and P(X=2) separately and ensure that their sum is 1.
7. How do the questions in RS Aggarwal's Probability chapter differ from the NCERT textbook?
While NCERT provides the fundamental concepts and standard problems, RS Aggarwal expands on them significantly. The key difference lies in the volume and variety of questions. RS Aggarwal includes a larger number of practice problems, covering more complex and varied scenarios for each topic like conditional probability and Bayes' theorem. This makes it an excellent supplementary resource for students aiming to achieve a higher score by mastering a wider range of applications.

















