11) (3 1/3)⁷ : (3 1/3)⁵ · 3 1/3

\(3\dfrac13=\dfrac{10}{3}\).

\(\left(\dfrac{10}{3}\right)^7:\left(\dfrac{10}{3}\right)^5\cdot\dfrac{10}{3}=\left(\dfrac{10}{3}\right)^{7-5+1}=\left(\dfrac{10}{3}\right)^3=\dfrac{1000}{27}\).

Ответ: \(\dfrac{1000}{27}\)