Chapter 12.7, Problem 42PPE

To determine

To find: The probability of choosing a blue marble and explain.

Answer to Problem 42PPE

The probability of choosing a blue marble is $\frac{3}{10}$ .

Explanation of Solution

Given:

The odd in favor of choosing a red marble from a bag of red and blue marbles are $7:3$ .

Calculation:

The number of unfavorable outcome is 3 for blue marble so it will be the number of favorable outcome for finding its probability.

Find the probability of choosing a blue marble.

  $\begin{array}{c}\text{P}\left(\text{ event}\right)=\frac{\text{number}\text{of}\text{favorable}\text{outcomes}}{\text{number}\text{of}\text{possible}\text{outcomes}}\\ \text{P}\left(\text{blue}\right)=\frac{3}{3+7}\\ =\frac{3}{10}\end{array}$ .

Therefore, the probability of choosing a blue marble is $\frac{3}{10}$ .