## 13.4.2 Simple Probability, PT3 Focus Practice

Question 5: A box contains 36 green erasers and a number of red erasers. If an eraser is picked randomly from the box, the probability of picking a red eraser is 5 8 . Find the number of red erasers. Solution: Probability of picking a green eraser = 1 – 5 8 = 3 8 … Read more

## 13.4.1 Simple Probability, PT3 Focus Practice

Question 1: A box contains 5 pink marbles and 21 yellow marbles. Sharon puts another 4 pink marbles and 1 yellow marble inside the box. A marble is chosen at random from the box. What is the probability that a pink marble is chosen? Solution: Total number of pink marbles = 5 + 4 = … Read more

## 13.2.2 Probability Theory involving Equally Likely Outcomes (2)

(D) Elements of a Sample Space which Satisfy Given Condition When a specific condition is given, we can list the elements of a sample space which satisfy the given condition.   Example 1: A two-digit number which is not more than 25 is chosen at random. List the elements of the sample space which satisfy each of … Read more

## 13.2.1 Probability Theory involving Equally Likely Outcomes (1)

13.1 Sample Space   (A) Experiment 1. An experiment is a process or an action in making an observation to obtain the required results. 2. The result of the experiment is called the outcome. (B)    Listing all the possible outcomes of an experiment We can list all the possible outcomes of an experiment by carrying out … Read more

## 13.1 Simple Probability

(A) Probability of an Event 1. The probability of an event A, P(A) is given by 2. If P(A) = 0, then the event A will certainly not occur. 3. If P(A) = 1, then the event A will certainly to occur. Example 1: Table below shows the distribution of a group of 80 pupils playing a game. … Read more