Question

Suppose for a cookout you need to make 100 hamburgers. YOu know that 2 pounds will make 9 hamburgers. HOw many pounds will you need?

Answer 1

$\bf \begin{array}{ccll} lbs&burgers\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 2&9\\ x&100 \end{array}\implies \cfrac{2}{x}=\cfrac{9}{100}\implies \cfrac{2\cdot 100}{9}=x$