On the shelf, there are four books of poetry, four novels, and five reference works. Suppose we picked two books at random. What is the probability that we pick one novel and one reference work?
Choose the most appropriate option
A) 4/25 B) 6/31 C) 8/35 D) 10/39 E) 12/41
We could pick one novel and then one reference work, or, we could choose one reference work and then one novel.   P(one novel and one reference work) = 4/13*5/12 + 5/13*4/12 = 10/39   The answer is 10/39.
<result>D</result>
On the shelf, there are four books of poetry, four novels, and five reference works. Suppose we picked two books at random. What is the probability that we pick one novel and one reference work?