EX 2.1 two outputs

The simplest experiment to which probability applies is one with two possible outcomes.

For example

1. examining a single weld to see whether it is defective. The sample space for this experiment can be abbreviated as $\mathcal{S}=\{N,D\}$, where
   • $N$ represents not defective
   • $D$ represents defective,
   • the braces are used to enclose the elements of a set.
2. tossing a thumbtack and noting whether it landed point up or point down, with sample space $\mathcal{S}=\{U,D\}$
3. observing the gender of the next child born at the local hospital, with $\mathcal{S}=\{M,F\}$ .