Answer:
The correct option is b.
Step-by-step explanation:
It is given that y varies directly as x.
[tex]y\propto x[/tex]
[tex]y=kx[/tex]
It is given that y is 6 when x is 72.
[tex]6=k\times 72[/tex]
Divide both sides by 72.
[tex]\frac{1}{12}=k[/tex]
The constant of proportionality is [tex]\frac{1}{12}[/tex].
[tex]k=\frac{y}{x}[/tex]
[tex]\frac{1}{12}=\frac{y}{8}[/tex]
[tex]\frac{1}{12}\times 8=y[/tex]
[tex]\frac{2}{3}=y[/tex]
The value of y is [tex]\frac{2}{3}[/tex]. The correct option is b.
