Probability Class 10 Maths — Revision Notes
This chapter introduces probability theory and calculating chances of events. Students learn about sample space, outcomes, and theoretical vs experimental
TL;DR: This chapter introduces probability theory and calculating chances of events. Students learn about sample space, outcomes, and theoretical vs experime…
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This chapter introduces probability theory and calculating chances of events. Students learn about sample space, outcomes, and theoretical vs experimental
Basic Probability Concepts
- Probability P(E) = number of favorable outcomes / total number of possible outcomes
- Probability ranges from 0 to 1
- P(E) = 0 means event is impossible, P(E) = 1 means event is certain
- Sample space is set of all possible outcomes
Favorable Outcomes
- For coin: heads or tails, each has probability 1/2
- For dice: outcomes 1 to 6, each has probability 1/6
- For two dice: total 36 outcomes
- Playing cards: 52 cards, 4 suits, 13 cards per suit
Complementary and Compound Events
- P(E) + P(not E) = 1, so P(not E) = 1 - P(E)
- Two events: P(A or B) = P(A) + P(B) - P(A and B)
- Independent events: P(A and B) = P(A) x P(B)
- Dependent events: probability changes after first event
Theoretical vs Experimental
- Theoretical probability: calculated based on possibilities
- Experimental probability: calculated from actual experiments
- As number of trials increase, experimental approaches theoretical
- Law of large numbers: more trials, more accurate probability
Key Terms
- Probability: Measure of likelihood of event occurring between 0 and 1
- Sample Space: Set of all possible outcomes of an experiment
- Independent Events: Events where occurrence of one does not affect probability of other
Frequently Asked Questions
What is probability of getting sum of 7 when rolling two dice?
Favorable outcomes: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1) = 6 outcomes. Total outcomes = 36. Probability = 6/36 = 1/6.
How do you find P(A or B)?
Use formula P(A or B) = P(A) + P(B) - P(A and B). If A and B are mutually exclusive (cannot happen together), then P(A and B) = 0, so P(A or B) = P(A) + P(B).
More Class 10 Maths Revision Notes
- Real Numbers
- Polynomials
- Pair of Linear Equations in Two Variables
- Quadratic Equations
- Arithmetic Progressions
- Triangles
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