somebody help

$\dfrac{5}{6}\div \dfrac{3}{6}\times \dfrac{3}{15}\\ =\dfrac{5}{6}\div \dfrac{1}{2}\times \dfrac{1}{5}\\ =\dfrac{5}{6}\times 2 \times \dfrac{1}{5}\\ =\dfrac{5\times 2}{6\times 5}\\ =\dfrac{10}{30}\\ =\dfrac{1}{3}$