Skip to main content
\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)
Mathematics LibreTexts

5: Basic Concepts of Probability

  • Page ID
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    Course Goals and Anticipated Outcomes for This Chapter:

    Develop the students:

    • ability to do the counting
    • probabilistic reasoning 



    Thinking out Loud

    What do we mean if we say that the probability of tossing a coin and seeing a head is about 0.5 (50%, or the odds are 50/50)?

    One possible answer: We are claiming that if you toss the coin in question a large number of times then you should see heads appearing about half of the time.

    Thinking out loud

    What do people mean when they refer to a "100 year" flood?

    One possible answer: They are claiming that the likelihood of a flood of that magnitude happening in any given year is 0.01 (1%, or the odds are 1/100).