PROBABILITY
Definition Of Probability
Probability is a numerical measure of the likelihood of occurrence of an event. The value of probability lies between 0 and 1.
If all outcomes of an experiment are equally likely, then the probability is given by, Probability of an event = 
Video Examples: Introduction to Probability
Example of Probability
The probability to pick a blue marble from a basket containing 10 blue marbles is 1.
Suppose you toss a fair coin. Then the probability of tossing a head or tail is 1/2
Solved Example on Probability
Ques: A basket contains 30 apples, 20 pears and 10 peaches. What is the probability that the first piece of fruit taken from the basket will be a peach?
Choices:
A. 1/3
B.1/2
C.1/6
D.1/5
Correct Answer: C
Solution:
Step 1: Total number of fruits in the basket = 30 + 20 + 10 = 60.
Step 2: Number of peaches in the basket = 10.
Step 3: The probability of taking a peach from the basket 10/60 =1/6 . [From the definition.]
Quick Summary
- Probability measures the likelihood of an event.
- Probability values range from 0 to 1.
- Equally likely outcomes allow for simple probability calculation.
🍎 Teacher Insights
Use real-world examples like coin flips, dice rolls, and card draws to illustrate probability concepts. Emphasize the importance of identifying all possible outcomes and favorable outcomes.🎓 Prerequisites
- Basic Arithmetic
- Fractions
Check Your Knowledge
Q1: A bag contains 5 red marbles and 3 blue marbles. What is the probability of picking a blue marble?
Q2: If you roll a fair six-sided die, what is the probability of rolling a 4?
Frequently Asked Questions
Q: What does a probability of 0 mean?
A: A probability of 0 means the event is impossible and will never occur.
Q: What does a probability of 1 mean?
A: A probability of 1 means the event is certain and will always occur.