Dividing by a fraction is the same as multiplying by the inverse of the fraction (i.e. the fraction where you switch numerator and denominator):
[tex]x\div \dfrac{a}{b}=x\cdot \dfrac{b}{a}[/tex]
So, you have
[tex]\dfrac{3}{5}\div\dfrac{1}{3}=\dfrac{3}{5}\cdot\dfrac{3}{1}=\dfrac{3}{5}\cdot 3=\dfrac{9}{5}[/tex]
