Laske.

a) [[$ \dfrac{3}{5} \cdot \dfrac{1}{2} \cdot \dfrac{3}{4} $]] =

b) [[$ \dfrac{4}{5} \cdot \dfrac{6}{7} \cdot \dfrac{8}{9} $]] =

c) [[$ 2 \dfrac{1}{3} \cdot 5 \dfrac{4}{7} $]] =

d) [[$ 3 \dfrac{1}{5} \cdot 6 \dfrac{2}{5} $]] =