Mr. Jay has 100 pairs of shoes in his closet. He has 26 brown pairs, 12 navy pairs, 47 black pairs, and 15 white pairs. What is P(brown|black)

?(1 point)
Responses

26100+4799
Start Fraction 26 over 100 End Fraction plus Start Fraction 47 over 99 End Fraction

26100
Start Fraction 26 over 100 End Fraction

26100⋅4799
Start Fraction 26 over 100 End Fraction times Start Fraction 47 over 99 End Fraction

26100⋅47100

1 answer

To find \( P(\text{brown} | \text{black}) \), which is the probability of selecting a brown pair of shoes given that a black pair has been selected, we can use the formula for conditional probability. The formula is:

\[ P(A | B) = \frac{P(A \cap B)}{P(B)} \]

Where:

  • \( A \) is the event of selecting a brown pair.
  • \( B \) is the event of selecting a black pair.
  1. Identify \( P(B) \), the total probability of selecting a black pair:

    • There are 47 black pairs of shoes out of 100 pairs in total.
    • Thus, \( P(B) = \frac{47}{100} \).
  2. Identify \( P(A \cap B) \), the probability of selecting a pair that is both brown and black. Since pairs cannot be both brown and black at the same time (they are distinct categories), this implies that:

    • \( P(A \cap B) = 0 \).
  3. Calculate \( P(A | B) \): \[ P(\text{brown} | \text{black}) = \frac{P(\text{brown} \cap \text{black})}{P(\text{black})} = \frac{0}{\frac{47}{100}} = 0 \]

Since it is not possible to have a pair of shoes that is both brown and black, the probability \( P(\text{brown} | \text{black}) \) is \( 0 \).

The answer choice that corresponds to a zero probability isn't provided, but logically, it is \( 0 \).