A bag contains seven red balls numbered 2, 4, 5, 6, 7, 8, 10 and three white bal
numbered 1, 3, and 9. If a ball is drawn, what is the probability the ball is red or
even? Show all work and round all decimals to 3 places or percents to the neare
tenth, if needed.



Answer :

Step-by-step explanation:

To find the probability that a ball drawn from the bag is either red or even, we need to use the principle of counting and probability.

First, let's identify all the relevant information:

1. **Total number of balls**:

There are 7 red balls and 3 white balls, so the total number of balls is:

\[

7 + 3 = 10

\]

2. **Red balls**:

The red balls are numbered: 2, 4, 5, 6, 7, 8, 10.

3. **White balls**:

The white balls are numbered: 1, 3, 9.

4. **Even numbered balls**:

The even numbers among all the balls are: 2, 4, 6, 8, 10.

Next, we will find the probability of each event:

- **Probability of drawing a red ball (P(Red))**:

The number of red balls is 7.

\[

P(\text{Red}) = \frac{\text{Number of red balls}}{\text{Total number of balls}} = \frac{7}{10}

\]

- **Probability of drawing an even-numbered ball (P(Even))**:

The number of even-numbered balls is 5 (2, 4, 6, 8, 10).

\[

P(\text{Even}) = \frac{\text{Number of even-numbered balls}}{\text{Total number of balls}} = \frac{5}{10} = \frac{1}{2}

\]

- **Probability of drawing a ball that is both red and even (P(Red ∩ Even))**:

The red balls that are also even are: 2, 4, 6, 8, 10 (5 balls).

\[

P(\text{Red and Even}) = \frac{\text{Number of red and even balls}}{\text{Total number of balls}} = \frac{5}{10} = \frac{1}{2}

\]

To find the probability of drawing a ball that is either red or even, we use the formula for the union of two events:

\[

P(\text{Red or Even}) = P(\text{Red}) + P(\text{Even}) - P(\text{Red and Even})

\]

Substituting the values:

\[

P(\text{Red or Even}) = \frac{7}{10} + \frac{5}{10} - \frac{5}{10} = \frac{7}{10}

\]

Therefore, the probability that the ball drawn is either red or even is:

\[

P(\text{Red or Even}) = \frac{7}{10} = 0.7

\]

To express this probability as a percentage, we multiply by 100:

\[

0.7 \times 100 = 70\%

\]

Thus, the probability that a ball drawn is either red or even is \( 0.700 \) or 70.0%.