Given data:
5/7 cup of butter to make 4 dozen cookies
? cup of butter to make 18 dozen cookies
Use a rule of three:
[tex]\begin{gathered} ?=\frac{18*\frac{5}{7}}{4} \\ \\ ?=\frac{\frac{90}{7}}{4} \\ \\ ?=\frac{90}{7*4} \\ \\ ?=\frac{90}{28} \\ \\ ?=\frac{45}{14}=\frac{42}{14}+\frac{3}{14}=3\frac{3}{14} \end{gathered}[/tex]Then, there are required 45/14 (or 3 3/14) cups of butter to make 18 dozen of cookies
