Chapter 8.6, Problem 7E

To determine

To write: the probability of an certainevent $S$ .

Answer to Problem 7E

Probability of an certain event is $P\left(S\right)=1$ .

Explanation of Solution

Given:

Probability of an event $S$ .

If an event E has $n\left(E\right)$ equally likely outcomes and its sample space S has $n\left(S\right)$ equally likely outcomes, then the probability of event E is $P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}$ .

If the occurred event is acertain event, then the probability of the event will be 0.

As, for certain event $n\left(S\right)$

So,

  $\begin{array}{l}P\left(S\right)=\frac{n\left(S\right)}{n\left(S\right)}\\ P\left(S\right)=1\end{array}$