6 3 28 / 7 9 30 =

\( \frac{6}{7} : \frac{3}{9} : \frac{28}{30} = \frac{6}{7} \times \frac{9}{3} \times \frac{30}{28} = \frac{6 \times 9 \times 30}{7 \times 3 \times 28} = \frac{1620}{588} = \frac{135}{49} \)

Ответ: \( \frac{135}{49} \)