You are here
Theoretical Probability
Last updated at June 5, 2026 by Teachoo
Class 9
Chapter 7 - The Mathematics of Maybe: Introduction to Probability
- Definition
- Exercise Set 7.1
-
Experimental and Theoretical Probability
- Analysing Statistical Data Using Probability
- Exercise Set 7.2
- Elements of Probability
- Exercise Set 7.3
- Tree Diagrams
- Exercise Set 7.4
- End-of-Chapter Exercises
Transcript
Theoretical Probability This is what you expect to happen in an ideal, perfectly fair situation without ever actually running an experiment. It assumes that every possible outcome is equally likely Our formula is Let’s look at some examples P( event )=" (Number of FAVORABLE Outcomes) " /" (Total Number of POSSIBLE Outcomes) " EXAMPLE 1: TOSSING A FAIR COIN Heads Tails Total Outcomes: H, T (2) Calculate P (landing on heads) P(" Heads ")=1/2=0.5=50% EXAMPLE 2: ROLLING A SIX-SIDED DIE Total Outcomes: 1, 2, 3, 4, 5, 6 (6) alculate P(rolling a 4) P(4)=1/6 P(rolling an even number) Outcomes: 2, 4, 6 (3) P( Even )=3/6=1/2=50% EXAMPLE 3: PICKING MARBLES FROM A BAG otal Marbles: 10 ◯ ◯ Red Yellow loull Calculate P(picking a Blue marble) P(" Blue ")=5/10=1/12=50% Calculate P(picking a Red marble) P(" Red ")=3/10=30%
