Question

If i have 480 grams of pasta for 4 people how many kilograms will i need for 14 people

Answer 1

$\bf \begin{array}{ccll} \stackrel{pasta}{grams}&people\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 480&4\\ g&14 \end{array}\implies \cfrac{480}{g}=\cfrac{4}{14}\implies \cfrac{480}{g}=\cfrac{2}{7} \\\\\\ \cfrac{480\cdot 7}{2}=g\implies 1680=g$

now, there are 1000 grams in one Kilogram, so in 1680 grams, there are 1680/1000 Kilograms, namely 1.680.