A Venn diagram is a way to illustrate events and are particularly useful when outcomesoverlap
Venn diagrams are mostly used for 2 or 3 events
A Venn diagram consists of a box (rectangle) and a bubble (circle/ellipse) for each event
Bubbles may or may not overlap
Bubble(s) is not a technical term, but we like it!
The box represents alloutcomes
There is no standardised symbol for this purpose
Bubbles are labelled with their event name (A, B, etc)
The numbers inside a Venn diagram (there should be one in each region) will represent either a frequency or a probability
In the case of probabilities being shown, all values should total 1
What do the different regions and bubbles overlapping mean on a Venn diagram?
This will depend on how many events there are and how the outcomes overlap
Venn diagrams show ‘AND’ and ‘OR’ statements easily
Worked Example
Exam Tip
The rectangle in a Venn diagram is a key part of the diagram
it represents all possible outcomes of the experiment
the bubbles merely represent the events we are particularly interested in
there is usually a few possibilities that fall outside of these events so this would be the section outside the bubbles but inside the rectangle
A quick ‘mini-Venn’ diagram shading the parts required to answer the question can be useful rather than always drawing a full Venn diagram with all its values