[tex]x:11 = \frac{1}{3} :6[/tex]
[tex] \frac{x}{11} = \frac{ \frac{1}{3} }{6} \\ \frac{x}{11} = \frac{1}{18} [/tex]
[tex]11 \times \frac{x}{11} = 11 \times \frac{1}{18} [/tex]
[tex]x = 11 \times \frac{1}{18} [/tex]
[tex]x = \frac{11}{18} [/tex]