[tex]1 Pasta=\frac{18}{8}+\frac{5}{8}=\frac{23}{8 }[/tex] pounds of flour
We create a proportion:
[tex]1(pastas)=\frac{23}{8 } [/tex]
[tex]X=86[/tex]
[tex]86=\frac{23}{8 }x[/tex]
[tex]86=2.875x[/tex]
[tex]x=29.91[/tex]
Chef will be able to make [tex]29[/tex] Pastas and eat what's left :)