Lesson

Many situations in probability can be organised into Venn diagrams, arrays, and tree diagrams to organise the information, determine the size of different groups and do calculations.

The formulas and notation encountered can also help us to organise the information given in a question and calculate different probabilities.

Given that P(A \cap B) =0.2 and P(A \cap B')=0.3.

a

What is the value of P(A)?

Worked Solution

b

What is the value of P(B), given that the events are independent?

Worked Solution

c

Given that A and B are independent find P(A \cup B').

Worked Solution

Consider the following probability Venn Diagram:

Find P(A|B).

Worked Solution

Idea summary

Probability can be organised into Venn diagrams, arrays, and tree diagrams to organise the information to help solve problems.

We can also use the formulas for complementary events, compound events, independent events and conditional probability to solve problems.