Venn diagrams and sets · Grade 11
In Grade 11 you learn: probability from Venn diagrams and set notation.
A Venn diagram sorts things into overlapping circles inside a rectangle. The rectangle is the universal set ξ. The diagram makes it easy to count the items in one group, in both, in either or in neither. It also helps you find probabilities.
Key facts
- A′ (complement): not in A.
- Fill in a Venn diagram from the middle (the overlap) outwards.
Worked examples
Example 1
The Venn diagram has 50 members. Find x, then P(B | A).
Answer: x = 10; P(B | A) = 1/3