Probability Different Colors 53Dad2
1. **Problem Statement:**
We have two jars: Jar A with 6 green and 4 red balls, Jar B with 2 green and 8 red balls. One ball is drawn from each jar. Given that the balls drawn have different colors, find the probability that the ball from Jar B is green.
2. **Define Events:**
Let:
- $G_A$ = ball from Jar A is green
- $R_A$ = ball from Jar A is red
- $G_B$ = ball from Jar B is green
- $R_B$ = ball from Jar B is red
3. **Calculate individual probabilities:**
- $P(G_A) = \frac{6}{10} = 0.6$
- $P(R_A) = \frac{4}{10} = 0.4$
- $P(G_B) = \frac{2}{10} = 0.2$
- $P(R_B) = \frac{8}{10} = 0.8$
4. **Event of different colors:**
This can happen in two ways:
- Jar A green and Jar B red: $P(G_A \cap R_B) = P(G_A) \times P(R_B) = 0.6 \times 0.8 = 0.48$
- Jar A red and Jar B green: $P(R_A \cap G_B) = P(R_A) \times P(G_B) = 0.4 \times 0.2 = 0.08$
5. **Total probability of different colors:**
$$P(\text{different colors}) = 0.48 + 0.08 = 0.56$$
6. **Find the conditional probability that the ball from Jar B is green given different colors:**
We want $P(G_B | \text{different colors})$.
By definition of conditional probability:
$$P(G_B | \text{different colors}) = \frac{P(G_B \cap \text{different colors})}{P(\text{different colors})}$$
Since $G_B$ and different colors means the case where Jar A is red and Jar B is green:
$$P(G_B \cap \text{different colors}) = P(R_A \cap G_B) = 0.08$$
Therefore:
$$P(G_B | \text{different colors}) = \frac{0.08}{0.56} = \frac{8}{56} = \frac{1}{7}$$
7. **Final answer:**
The probability that the ball drawn from Jar B is green given the balls have different colors is $\boxed{\frac{1}{7}}$.
This corresponds to option D.