Question

a bookshelf contains 9 mysteries, 7 biographies, and 4 science fiction books. a book is randomly selected, not replaced, then another is selected. find the probability of selecting a biography then a mystery. 63/380 63/400 7/95 7/100 77/350

Explanation:

Step1: Calculate total books

Total books = 9 + 7 + 4 = 20

Step2: Probability of first biography

Probability = $\frac{7}{20}$ (7 biographies out of 20)

Step3: Probability of second mystery

After removing 1 book, total = 19; mysteries = 9. Probability = $\frac{9}{19}$

Step4: Multiply probabilities

Combined probability = $\frac{7}{20} \times \frac{9}{19} = \frac{63}{380}$

Answer:

A. 63/380