Question

A recipe uses 6 cups of cheese to serve 30 people. How much cheese is needed for 50 people

Answer 1

$\bf \begin{array}{ccll} \stackrel{cheese}{cups}&people\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 6&30\\ c&50 \end{array}\implies \cfrac{6}{c}=\cfrac{30}{50}\implies \cfrac{6\cdot 50}{30}=c$