[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\red{sw}}{\orange{er}} {\color{yellow}{:}}}}}[/tex]
let length of the rectangle be x
so, from the question
[tex] \frac{5}{6} = \frac{x}{30} \\ [/tex]
by cross multiplication,
[tex]150 = 6x \\ x = \frac{150}{6} \\ x = 25[/tex]