One in 9 ships is likely to be wrecked, when they are set on sail. When 6 ships set on sail, the probability for exactly, 3 will not arrive safely is

p= probability that the ship will be wrecked =$\frac{1}{9}$

q=probability that the ship will  arrive safely =$\frac{8}{9}$

If  n=6 then the  probability of 3 ships will not arrive safely=P(x = 3)=$$\begin{gathered} =n{C}_r{\left(q\right)}^{n-r}{\left(p\right)}^r \\ {=}^6{C}_3{\left(\frac{1}{9}\right)}^3{\left(\frac{8}{9}\right)}^3{=}^6{C}_3\left(\frac{8^3}{9^6}\right) \end{gathered}$$