Eight balls numbered 1 to 8 are placed in a bag. Some of the balls are grey, and some are white. The balls numbered [tex]$1, 2, 5,$[/tex] and [tex]3[/tex] are grey. The balls numbered [tex]$3, 4, 6,$[/tex] and [tex]8[/tex] are white. A ball will be selected from the bag at random. The 8 possible outcomes are listed below. Note that each outcome has the same probability:

(1) (2) (3) (4) (5) (6) (7) (8)

Complete parts (a) through (c). Write the probabilities as fractions.

(a) Check the outcomes for each event below. Then, enter the probability of the event:

- Event A: Selecting a grey ball
- Event B: Selecting a white ball

(b) Compute the following:

[tex]P(A) + P(B) - P(A \text{ and } B) = \square[/tex]

(c) Select the answer that makes the equation true:

[tex]P(A) + P(B) - P(A \text{ and } B) = \text{ (Choose one)} \square[/tex]



Answer :

Certainly! Let's go through the solution step-by-step.

(a) To find the probabilities of each event:
- Event A: Drawing a grey ball.
- Event B: Drawing a white ball.

Total number of outcomes: 8

Grey balls: Numbered [tex]\(1, 2, 5, 3\)[/tex]. So, there are 4 grey balls.
White balls: Numbered [tex]\(3, 4, 6, 8\)[/tex]. So, there are 4 white balls.

i. Probability of Event [tex]\(A\)[/tex] (drawing a grey ball):
[tex]\[ P(A) = \frac{\text{Number of grey balls}}{\text{Total number of outcomes}} = \frac{4}{8} = 0.5 \][/tex]

ii. Probability of Event [tex]\(B\)[/tex] (drawing a white ball):
[tex]\[ P(B) = \frac{\text{Number of white balls}}{\text{Total number of outcomes}} = \frac{4}{8} = 0.5 \][/tex]

iii. Probability of Event [tex]\(A \text{ and } B\)[/tex] (a ball that is both grey and white):
Notice that ball number 3 is both grey and white, so:
[tex]\[ P(A \text{ and } B) = \frac{\text{Number of balls that are both grey and white}}{\text{Total number of outcomes}} = \frac{1}{8} = 0.125 \][/tex]

(b) Compute the combined probability:

Using the formula for the union of two events:
[tex]\[ P(A \cup B) = P(A) + P(B) - P(A \text{ and } B) \][/tex]

Plugging in the values:
[tex]\[ P(A \cup B) = 0.5 + 0.5 - 0.125 = 0.875 \][/tex]

So, the combined probability is [tex]\(0.875\)[/tex].

(c) Select the answer that makes the equation true:

Given:
[tex]\[ P(A) + P(B) - P(A \text{ and } B) = 0.875 \][/tex]

The answer that makes the equation true is [tex]\(0.875\)[/tex].

In summary:
1. [tex]\( P(A) = 0.5 \)[/tex]
2. [tex]\( P(B) = 0.5 \)[/tex]
3. [tex]\( P(A \text{ and } B) = 0.125 \)[/tex]
4. [tex]\( P(A \cup B) = 0.875 \)[/tex]

So, the completed answers are:
[tex]\[ \begin{aligned} &\text{(a) } P(A) = 0.5, P(B) = 0.5, P(A \text{ and } B) = 0.125 \\ &\text{(b) } P(A) + P(B) - P(A \text{ and } B) = 0.875 \\ &\text{(c) } \text{The answer that makes the equation true is } 0.875 \end{aligned} \][/tex]