Question

Nadia’s bookshelf contains 10 fiction books, two reference books, and five nonfiction books. What is the probability that she randomly picks up a reference book and then, without replacing it, picks up a nonfiction book?

Answer 1

Answer:

5/136

Probability is the chance of an event happening.

Probability = (Favorable outcome)/(total outcome)

P(r and n) = 2/17 × 5/16

=(2 × 5)/(17 × 16)

= 10/272

= 5/136

Answer 2

Answer:

5/136, or about 3.68%

Step-by-step explanation:

There are 17 total books on the bookshelf and only two of them are reference books, so the probability that you randomly grab a reference book is 2 out of 17, or 2/17.

Now that you took out a reference book (and did not put it back) there are 16 books on the bookshelf and you know five of them are nonfiction. That means the probability of getting a nonfiction book on your second grab is 5/16.

To find the probability that both of these events happen, you multiply the two fractions together.

2/17 x 5/16 = 10/272, which can reduce to 5/136, or about 3.68%