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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

Respuesta :

I think it would be D.


5/9 *5/9 = 25/81 
it's correct,

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)

=[tex]\dfrac{5}{9}\times \dfrac{5}{9}[/tex]

=25/81

Hence, probability that both selections were fiction books is:

d) 25/81