Events as Subsets of Outcomes
Aligned to S-CP.A.1 — Common Core State Standards for Mathematics.
What this lesson teaches
The sample space is the set of all possible outcomes, and an event is a subset of it. You combine events with unions (A or B), intersections (A and B), and complements (not A).
Worked example
Roll a fair die, sample space {1,2,3,4,5,6}. Let A = even = {2,4,6} and B = greater than 3 = {4,5,6}. Then A and B (intersection) = {4,6}, A or B (union) = {2,4,5,6}, and not A (complement) = {1,3,5}.
Practice questions
- List the sample space for flipping two coins.
- For a die, write the event 'less than 3' as a subset.
- Given A = {1,2,3} and B = {2,3,4}, find A ∩ B and A ∪ B.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Eventos como Subconjuntos de Resultados
El espacio muestral es el conjunto de todos los resultados posibles, y un evento es un subconjunto de él. Combinas eventos con uniones (A o B), intersecciones (A y B) y complementos (no A).
Ejemplo: Lanza un dado justo, espacio muestral {1,2,3,4,5,6}. Sea A = par = {2,4,6} y B = mayor que 3 = {4,5,6}. Entonces A y B (intersección) = {4,6}, A o B (unión) = {2,4,5,6}, y no A (complemento) = {1,3,5}.
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