A bookshelf holds 24 mysteries, 12 non-fiction books, and 4 biographies. What is the probability of selecting a mystery book and then without replacing it, selecting a non-fiction book?

1 Answer
Feb 14, 2018

12/65 or roughly 18%

Explanation:

The bookshelf holds 24+12+4=40 books altogether.

First let’s find the probability of selecting a mystery book:

There are 24 mysteries out of 40 total books, so the probability is 24/40=60%

Now we need to select a non-fiction book out of the remaining 39 books. That probability would be 12/39=4/13

Using the counting principle we must multiply these numbers together on the numerator and denominator (basically just multiply the fractions), so:

3/5*4/13=12/65

Thus the probability is roughly 18%.