- Is the chance of an event happening.
- If a particular outcome can never occur, its probability is 0.
- If an outcome is certain to occur, its probability is 1.
- In general, if p is the probability that a specific outcome will occur, values of p fall in the range 0 <= p <= 1.
- Probability may be expressed as either a decimal, a fraction, or a ratio.
- Probability examples in everyday life include physical sciences, commerce, weather forecasting, board games, sports statistics, etc.
What are the chances that the sun will shine this month? (likely)
What are the chances that you, a 11 year old boy, will be driving a car today? (unlikely)
What are the chances of tossing heads or tails on a coin? (equally likely)
Coin: 2 sides
The probability of rolling heads is 1/2
The probability of rolling tails is 1/2
Cube: 6 sides
Take a number cube and label the sides 1 - 6.
The probability of rolling a 3 is one outcome out of a total of six possible outcomes, that is 1/6.
Similarly, the probability of rolling a 5 is also 1/6.
The probability of rolling an odd number (1, 3, 5) = three outcomes out of a total of six possible outcomes = 3/6 = 1/2
Probability of rolling an even number is also same as rolling an odd numbers (3/6 or 1/2).
Example: A bag contains 4 red balls and 3 green balls. What is the probability of picking a green ball?
Since there are three green and 1 is picked out at a time, the probability is 3/7.
Directions: Solve the following questions. Also write at least 10 examples of your own.