CBSE Class 11 Mathematics Chapter 16: Probability NCERT Solutions
This chapter provides essential NCERT Solutions for Class 11 Mathematics, focusing on Probability. It covers the fundamental concept of a sample space, which is the set of all possible outcomes of a random experiment. The solutions guide students through defining sample spaces for experiments like tossing a coin multiple times, throwing a die repeatedly, and combining these actions. Understanding sample spaces is crucial for calculating probabilities of events. These solutions offer clear, step-by-step explanations, helping students grasp the basic principles of probability and prepare effectively for their examinations by reinforcing theoretical knowledge with practical examples.
Quick info
| Board | CBSE |
|---|---|
| Class | Class 11 |
| Subject | Mathematics |
| Session | 2026 |
| Language | English |
| Type | NCERT Solutions |
| Chapter | Chapter 16: Probability |
Chapter summary
Chapter 16 on Probability for Class 11 Mathematics NCERT Solutions introduces the foundational concept of a sample space. The exercises focus on identifying and describing the set of all possible outcomes for various random experiments, such as tossing coins or rolling dice. These solutions provide a clear understanding of how to systematically list all potential results, which is the first step in solving probability problems.
Learning outcomes
- Understand the concept of a sample space in probability.
- Identify all possible outcomes for simple random experiments.
- Describe the sample space for tossing a coin multiple times.
- Describe the sample space for throwing a die multiple times.
- Determine the sample space for combined experiments (coin toss and die roll).
Topics covered
Paper topics
- Sample Space
- Random Experiment
- Outcomes
- Coin Toss Experiment
- Die Throw Experiment
- Multiple Coin Tosses
- Multiple Die Throws
- Combined Experiments
Important topics
- Definition of Sample Space
- Listing Outcomes for Coin Tosses
- Listing Outcomes for Die Throws
- Calculating Total Outcomes
- Sample Space for Combined Events
PDF preview
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Questions and Solutions
Question 1
A coin has two possible outcomes when tossed: a Head (H) or a Tail (T).
When a coin is tossed three times, each toss is an independent event. To find the total number of possible outcomes, we multiply the number of outcomes for each toss: 2 outcomes × 2 outcomes × 2 outcomes = = 8 outcomes.
The sample space (S) is the set of all these possible outcomes. Therefore, the sample space is:
Question 2
When a standard six-sided die is thrown once, the possible outcomes are the numbers 1, 2, 3, 4, 5, or 6.
When the die is thrown two times, the outcome of each throw is recorded. We can represent the sample space as a set of ordered pairs , where is the result of the first throw and is the result of the second throw. Both and can be any integer from 1 to 6.
The total number of possible outcomes is the product of the number of outcomes for each throw: 6 outcomes × 6 outcomes = .
The sample space is given by:
Listing all 36 pairs explicitly:
Question 3
A coin has two possible outcomes for each toss: Head (H) or Tail (T).
When a coin is tossed four times, the total number of possible outcomes is calculated by multiplying the number of outcomes for each toss: 2 × 2 × 2 × 2 = = 16 outcomes.
The sample space (S) is the collection of all these distinct possible outcomes. Thus, the sample space is:
Question 4
A coin has two possible outcomes: Head (H) and Tail (T).
A standard six-sided die has six possible outcomes: the numbers 1, 2, 3, 4, 5, or 6.
When a coin is tossed and a die is thrown simultaneously, each outcome consists of a result from the coin toss paired with a result from the die throw. The total number of possible outcomes is the product of the number of outcomes for each event: 2 outcomes (coin) × 6 outcomes (die) = 12 outcomes.
The sample space (S) is the set of all these combined outcomes:
Common mistakes
- Failing to list all possible outcomes in the sample space.
- Incorrectly calculating the total number of outcomes.
- Missing combinations in sample spaces for combined experiments.
- Confusing outcomes with events.
Revision tips
- Focus on clearly defining the experiment before listing outcomes.
- Use systematic methods (like tree diagrams, though not explicitly shown here) to ensure all outcomes are captured.
- Practice listing sample spaces for variations of coin tosses and die rolls.
- Review the definition of a sample space before attempting problems.
Practice MCQs
Q1. What is the sample space for tossing a coin once?
Explanation: When a coin is tossed once, the possible outcomes are getting a Head (H) or a Tail (T). Therefore, the sample space is {H, T}.
Q2. How many possible outcomes are there when a coin is tossed three times?
Explanation: For each toss of a coin, there are 2 possible outcomes. When tossed three times, the total number of outcomes is 2 × 2 × 2 = 2^3 = 8.
Q3. What does the notation (x, y) represent in the sample space of throwing a die twice?
Explanation: In the sample space for throwing a die twice, (x, y) represents an ordered pair where 'x' is the result of the first throw and 'y' is the result of the second throw.
Q4. If a coin is tossed and a die is thrown, what is one possible outcome in the sample space?
Explanation: When a coin is tossed and a die is thrown, the outcomes combine a coin face (H or T) with a die number (1-6). 'T3' represents getting a Tail on the coin and a 3 on the die.
Q5. What is the total number of outcomes when a die is thrown two times?
Explanation: A die has 6 possible outcomes. When thrown twice, the total number of outcomes is 6 × 6 = 36.
Frequently asked questions
What is a sample space in probability?
A sample space is the set of all possible outcomes that can occur when a random experiment is performed.
How do you find the sample space for tossing a coin three times?
For each toss, there are two outcomes (H or T). For three tosses, you list all combinations: HHH, HHT, HTH, HTT, THH, THT, TTH, TTT. The total number of outcomes is 2^3 = 8.
What is the sample space when a die is thrown two times?
The sample space consists of ordered pairs (x, y) where x and y can be any number from 1 to 6. There are 6 × 6 = 36 possible outcomes.
How do these NCERT solutions help Class 11 students?
These solutions provide clear, step-by-step explanations for defining sample spaces, which is a fundamental concept in probability, aiding students in understanding and solving related problems for exams.
Are the questions in these solutions the same as the NCERT textbook?
Yes, the questions are kept exactly the same as in the NCERT textbook, ensuring students can follow along with their studies. The solutions, however, are rewritten for clarity and better understanding.
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