Question

The question is in the image that is attached :)

Answer 1

So hmm check the picture below

$\bf \qquad \qquad \textit{direct proportional variation}\\\\ \textit{\underline{y} varies directly with \underline{x}}\qquad \qquad y=kx\impliedby \begin{array}{llll} k=constant\ of\\ variation \end{array}\\\\ -------------------------------\\\\ \textit{we know that } \begin{cases} x=3\\ y=1 \end{cases}\implies 1=k3\implies \cfrac{1}{3}=k \\\\\\ thus\qquad \qquad y=\cfrac{1}{3}x$