Question

On a bookshelf, there are 5 fiction and 4 nonfiction books. Paul randomly selects one, puts it back, and then randomly selects another. What is the probability that both selections were fiction books?

a) 10/81
b) 16/81
c) 20/81
d) 25/81

Answer 1

I think it would be D.


5/9 *5/9 = 25/81
it's correct,

Answer 2

Answer with Step-by-step explanation:

On a bookshelf, there are 5 fiction and 4 nonfiction books.

Total books=5+4=9

P(selecting fiction book)=number of fiction books/total books

= 5/9

Paul randomly selects one, puts it back, and then randomly selects another.

Since, the selections are independent.

and P(A∩B)=P(A)×P(B)

where A and B are independent events

P(both selections were fiction books)

=P(first selection was fiction book)×P(second selection was fiction book)

=
`(5)/(9)* (5)/(9)`

=25/81

Hence, probability that both selections were fiction books is:

d) 25/81