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Flashcards · Maths · Probability

Venn Diagrams and Set Notation

16 cards

  1. What does the symbol \(\xi\) represent?

    The universal set, everything being considered.

  2. What does \(A \cap B\) mean?

    The overlap: items in both \(A\) and \(B\).

  3. What does \(A \cup B\) mean?

    Items in \(A\) or \(B\) or both.

  4. What does \(A'\) mean?

    Items not in \(A\), the complement.

  5. What does \(3 \in A\) mean?

    3 is a member of set \(A\).

  6. Where do you start when filling in a Venn diagram?

    In the overlap.

  7. How do you find "football only"?

    Subtract the number who play both from the number who play football.

  8. How do you find the number outside both circles?

    Subtract everyone inside the circles from the total.

  9. How do you find the probability of a region of a Venn diagram?

    The number in the region divided by the total in the rectangle.

  10. What is \(n(A \cup B)\) in terms of \(n(A)\), \(n(B)\) and \(n(A \cap B)\) (Higher tier)?

    \(n(A) + n(B) - n(A \cap B)\).

  11. If \(A = \{2, 4, 6, 8, 10\}\) and \(B = \{3, 6, 9\}\), what is \(A \cap B\)?

    \(\{6\}\).

  12. What is the union of \(A\) and \(B\) above?

    \(\{2, 3, 4, 6, 8, 9, 10\}\).

  13. What does the whole rectangle in a Venn diagram show?

    Everything in the universal set.

  14. What is the notation for the region in \(A\) but not in \(B\) (Higher tier)?

    \(A \cap B'\).

  15. Why is it wrong to add 18 and 14 to find the number playing at least one sport?

    The students who play both are counted twice.

  16. 22 play football, 19 play tennis, 5 play neither out of 40. How many play both?

    \(22 + 19 - 35 = 6\).