Chemistry - Aromatic Hydrocarbon Question with Solution | TestHub

In this molecule
$\mathrm{X}=\mathrm{n}\mathrm{o}$. of$1^{\mathrm{o}}-$carbon atoms
$\mathrm{Y}=\mathrm{n}\mathrm{o}$. of$2^{\mathrm{o}}-$carbon atoms
$\mathrm{Z}=\mathrm{n}\mathrm{o}$. of$3^{\mathrm{o}}-$carbon atoms
$\mathrm{M}=\mathrm{n}\mathrm{o}$. of$4^{\mathrm{o}}$$-$carbon atoms
What is the value of$\frac{\text{X}\text{+}\text{Y}\text{+}\text{Z}\text{+}\text{M}}{\text{2}}$?