There are 50 books on a shelf. They include 15 mystery novels, 12 works of historical fiction, 8 romance novels, and 15 nonfiction books. If Federica randomly selects 2 books from the shelf, what is the probability of selecting a historical fiction book on the first selection and selecting romance on the second selection? Assume the books are taken without replacement.(1 point)

Responses

1250⋅849
Start Fraction 12 over 50 End Fraction times Start Fraction 8 over 49 End Fraction

1250
Start Fraction 12 over 50 End Fraction

850
Start Fraction 8 over 50 End Fraction

1250⋅850
Start Fraction 12 over 50 End Fraction times Start Fraction 8 over 50 End Fraction

1 answer

To find the probability of selecting a historical fiction book first and a romance novel second, we can break down the problem step by step.

  1. Probability of selecting a historical fiction book first:

    • There are 12 historical fiction books out of a total of 50 books.
    • The probability \( P(HF) \) is given by: \[ P(HF) = \frac{12}{50} \]
  2. Probability of selecting a romance novel second (after selecting a historical fiction book):

    • After selecting one historical fiction book, there are now 49 books left on the shelf.
    • There are still 8 romance novels left.
    • The probability \( P(R | HF) \) of selecting a romance novel after already having selected a historical fiction book is given by: \[ P(R | HF) = \frac{8}{49} \]
  3. Combine the probabilities:

    • The total probability \( P(HF \text{ and } R) \) is calculated using the multiplication rule for independent events: \[ P(HF \text{ and } R) = P(HF) \times P(R | HF) \]

    Plugging in the probabilities: \[ P(HF \text{ and } R) = \frac{12}{50} \times \frac{8}{49} \]

  4. Final Probability Calculation: \[ P(HF \text{ and } R) = \frac{12 \times 8}{50 \times 49} = \frac{96}{2450} \]

Thus, the final answer for the probability of selecting a historical fiction book first and a romance book second is:

\[ \frac{12}{50} \times \frac{8}{49} \]

From your provided responses, the correct expression for the probability is:

\[ \frac{12}{50} \times \frac{8}{49} \]