For every 12 pibs there is 5 voys .
So for 1 pib the number of voys is
[tex]\begin{gathered} 12\text{PIB}=5\text{VOY} \\ 1\text{PIB}=\frac{5}{12}\text{VOY} \end{gathered}[/tex]There are 40 pibs in farm, So,
[tex]\begin{gathered} 40\text{ PIBS=40}\ast\frac{5}{12}\text{VOY} \\ =\frac{10\ast5}{3}=\frac{50}{3}=16\frac{2}{3}\text{VOY} \end{gathered}[/tex]