Class 10 Maths MCQ Test – Probability (Chapter 14) | Full Chapter Test

Class 10 Mathematics – Chapter: Probability (Detailed Notes)

These notes are designed for CBSE, GSEB and board exam preparation. Includes all concepts, formulas, and exam-oriented explanations.


1. What is Probability?

Probability means the chance of occurrence of an event.

  • Probability ranges between 0 and 1
  • 0 → Impossible event
  • 1 → Certain event

Example:

  • Getting head in a coin toss → probability = 1/2
  • Sun rising in east → probability = 1
  • Getting 7 on a dice → probability = 0

2. Experiment, Outcome and Event

  • Experiment: An action with uncertain result (e.g., tossing a coin)
  • Outcome: Possible result (Head or Tail)
  • Event: A group of outcomes

Example: Rolling a die

  • Sample space: {1,2,3,4,5,6}
  • Event (getting even number): {2,4,6}

3. Sample Space

The set of all possible outcomes is called sample space.

Notation: S

Example:

  • Coin → S = {H, T}
  • Dice → S = {1,2,3,4,5,6}

4. Classical Probability Formula

If all outcomes are equally likely:

\( P(E) = \frac{\text{Number of favourable outcomes}}{\text{Total number of outcomes}} \)

Important:

  • \( 0 \leq P(E) \leq 1 \)
  • \( P(\text{Sure event}) = 1 \)
  • \( P(\text{Impossible event}) = 0 \)

5. Types of Events

1. Sure Event

Event that will definitely occur.

2. Impossible Event

Event that cannot occur.

3. Simple Event

Event with only one outcome.

4. Compound Event

Event with more than one outcome.


6. Complementary Events

If E is an event, then its complement is denoted by \( E' \)

\( P(E) + P(E') = 1 \)

Example:

  • Event: Getting a head
  • Complement: Not getting a head (tail)

7. Probability with Dice

Total outcomes = 6

  • Even numbers → {2,4,6} → Probability = 3/6 = 1/2
  • Prime numbers → {2,3,5} → Probability = 3/6 = 1/2
  • Number > 4 → {5,6} → Probability = 2/6 = 1/3

8. Probability with Cards

Total cards = 52

  • Hearts = 13
  • Spades = 13
  • Diamonds = 13
  • Clubs = 13

Examples:

  • Probability of getting a heart = 13/52 = 1/4
  • Probability of getting a king = 4/52 = 1/13
  • Probability of red card = 26/52 = 1/2

9. Probability with Coins

Single coin:

  • S = {H, T}
  • P(H) = 1/2

Two coins:

  • S = {HH, HT, TH, TT}
  • P(2 heads) = 1/4
  • P(at least one head) = 3/4

10. Important Tips for Exams

  • Always write sample space first
  • Check if outcomes are equally likely
  • Simplify fraction at the end
  • Use complement when easier
  • Avoid calculation mistakes in counting outcomes

11. Solved Examples

Q1. Find probability of getting a number divisible by 3 when a die is thrown.

Numbers divisible by 3 → {3,6}

\( P = \frac{2}{6} = \frac{1}{3} \)

Q2. A card is drawn from a deck. Find probability of getting a queen.

Total queens = 4

\( P = \frac{4}{52} = \frac{1}{13} \)

Q3. Find probability of not getting a tail in coin toss.

\( P(\text{not tail}) = P(\text{head}) = \frac{1}{2} \)


⬇️ Attempt the test given below after revising these notes

Class 10 Maths - Probability Test

Class 10 Mathematics

Chapter 14 : Probability | Full Chapter MCQ Test

Time Left: 20:00
1. Probability of an impossible event is:
2. Total number of outcomes when a die is thrown:
3. Probability of getting a head in a coin toss:
4. Sample space of two coins:
5. Probability of getting an even number on a die:
6. Complementary probability formula:
7. Total cards in a deck:
8. Probability of a red card:
9. Probability always lies between:
10. Probability of sure event:
11. A card is drawn. Probability of king:
12. Number of outcomes in two dice:
13. Probability of sum = 7 (two dice):
14. Probability of prime on die:
15. Probability of tail:
16. If P(E)=0.3, then P(E'):
17. Probability of number less than 3 on die:
18. Probability of drawing a spade:
19. Probability of getting at least one head (2 coins):
20. If outcomes are not equally likely, we use:
Class 10 Maths Chapter 14: Probability Notes

Class 10 Mathematics Chapter 14: Probability

Probability is one of the most important and scoring chapters in Class 10 Mathematics. It helps students understand how to measure uncertainty and predict outcomes in real-life situations. This chapter forms the base for higher studies in statistics and data science.


Learning Outcomes

After completing this chapter, students will be able to:

  • Understand the concept of probability as a measure of chance.
  • Define experiment, outcome, event, and sample space.
  • Identify equally likely outcomes in experiments.
  • Apply the classical probability formula:
    • P(E) = Number of favourable outcomes / Total outcomes
  • Find probability in experiments involving coins, dice, and playing cards.
  • Understand complementary events and use:
    • P(E) + P(E') = 1
  • Solve real-life problems using probability concepts.
Exam Tip: Always write the sample space first before calculating probability. This step alone can fetch marks even if the final answer is incorrect.

Real Life Applications

Probability is widely used in everyday life and various fields:

  • Weather Forecasting: Predicting chances of rain or storms.
  • Games: Used in games like cards, dice, and lotteries.
  • Sports: Predicting winning chances of teams.
  • Insurance: Calculating risk and premium.
  • Medical Field: Estimating success rate of treatments.
  • Business: Decision making based on probability of outcomes.
Important Concept: Probability is always between 0 and 1. Values outside this range are mathematically incorrect.

Common Mistakes Students Make

  • Not writing the complete sample space.
  • Counting favourable outcomes incorrectly.
  • Forgetting that probability cannot be negative or greater than 1.
  • Confusing complementary events.
  • Making errors in cases like “at least”, “at most”, etc.
  • Not simplifying the final answer.
Pro Tip: In tricky questions, use complementary probability to simplify calculations (e.g., “at least one” type questions).

Conclusion

Probability is a simple yet powerful chapter. With proper understanding and practice, students can score full marks. Focus on clarity of concepts, accurate counting of outcomes, and regular practice of different types of questions.

Class 10 Maths Chapter 14: Probability - Solved Examples & FAQs

Class 10 Mathematics Chapter 14: Probability

10 Detailed Solved Examples

Example 1: Coin Toss

Find the probability of getting a head when a coin is tossed.

Solution:
Sample space S = {H, T}
Favourable outcomes = 1 (H)

P(H) = 1/2
Example 2: Dice Problem

Find the probability of getting an even number when a die is thrown.

Solution:
S = {1,2,3,4,5,6}
Even numbers = {2,4,6} → 3 outcomes

P = 3/6 = 1/2
Example 3: Card Problem

A card is drawn from a deck. Find probability of getting a king.

Solution:
Total cards = 52
Kings = 4

P = 4/52 = 1/13
Example 4: Complementary Event

Find probability of not getting a head.

Solution:
P(H) = 1/2
P(not H) = 1 − 1/2 = 1/2
Example 5: Two Coins

Find probability of getting two heads when two coins are tossed.

Solution:
S = {HH, HT, TH, TT}
Favourable = 1 (HH)

P = 1/4
Example 6: Sum of Dice

Find probability that sum is 7 when two dice are thrown.

Solution:
Total outcomes = 36
Favourable = (1,6),(2,5),(3,4),(4,3),(5,2),(6,1) → 6 outcomes

P = 6/36 = 1/6
Example 7: Prime Number on Die

Find probability of getting a prime number.

Solution:
Prime numbers = {2,3,5} → 3 outcomes

P = 3/6 = 1/2
Example 8: At Least One Head

Find probability of getting at least one head when two coins are tossed.

Solution:
S = {HH, HT, TH, TT}
Favourable = 3 (HH, HT, TH)

P = 3/4
Example 9: Number Less Than 4

Find probability of getting a number less than 4 on a die.

Solution:
Numbers = {1,2,3} → 3 outcomes

P = 3/6 = 1/2
Example 10: Complement Method

Find probability of getting at least one tail when two coins are tossed.

Solution:
P(no tail) = P(HH) = 1/4
P(at least one tail) = 1 − 1/4 = 3/4

10 Detailed FAQs

Q1: What is probability?
Probability is the measure of likelihood of an event occurring, ranging between 0 and 1.
Q2: What is sample space?
It is the set of all possible outcomes of an experiment.
Q3: What is an event?
An event is a subset of the sample space.
Q4: What is classical probability?
It is defined as favourable outcomes divided by total outcomes when all outcomes are equally likely.
Q5: What is complementary event?
If E is an event, then its complement E' is given by P(E') = 1 − P(E).
Q6: Can probability be greater than 1?
No, probability always lies between 0 and 1.
Q7: Why is probability important?
It helps in decision making and predicting outcomes in real life.
Q8: What are equally likely outcomes?
Outcomes having the same chance of occurring.
Q9: What is sure event?
An event that will definitely occur, with probability 1.
Q10: What is impossible event?
An event that cannot occur, with probability 0.

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