Chapter 12.8, Problem 8PPE

To determine

To find: The probability $P\left(4\text{or}\text{7}\right)$

Answer to Problem 8PPE

The probability $P\left(4\text{or}\text{7}\right)$ is $\frac{1}{5}$

Explanation of Solution

The expression for probability of an event is given by,

  $P\left(E\right)=\frac{\text{Favorable}\text{Outcomes}}{\text{Possible}\text{outcomes}}$

The probability of $P\left(\text{4}\text{or}\text{7}\right)$ is calculated as,

  $\begin{array}{c}P\left(\text{4}\text{or}\text{7}\right)=P\left(4\right)+P\left(7\right)\\ =\frac{1}{10}+\frac{1}{10}\\ =\frac{2}{10}\\ =\frac{1}{5}\end{array}$

Therefore, the probability of $P\left(4\text{or}\text{7}\right)$ is $\frac{1}{5}$ .