0.016
1) Considering that we have:
7 black balls
9 red balls
----------------------
16 balls
And 5 balls were randomly drawn.
2) We can write out:
As there was a replacement whenever we take a ball we put it back in the urn. Then the probability of taking 5 black balls is
[tex]\begin{gathered} P(5\text{ black balls)=(}\frac{7}{16})^5=\text{ }\frac{7}{16}\times\frac{7}{16}\times\frac{7}{16}\times\frac{7}{16}\times\frac{7}{16} \\ P(5\text{ black balls) = 0.016} \end{gathered}[/tex]3) Then the answer is 0.016