to find that out, let's divide 8 by (1+9+6) and distribute accordingly.
[tex]\bf \begin{array}{cccccc} \stackrel{butter}{1\left( \frac{8}{1+9+6} \right)}&:&\stackrel{flour}{9\left( \frac{8}{1+9+6} \right)}&:&\stackrel{sugar}{6\left( \frac{8}{1+9+6} \right)}\\\\\\ 1\left( \frac{1}{2} \right)&:&9\left( \frac{1}{2} \right)&:&6\left( \frac{1}{2} \right) \\\\\\ \cfrac{1}{2}&:&\cfrac{9}{2}&:&\cfrac{6}{2}\implies \cfrac{3}{1} \end{array}[/tex]
