How many hydroxy groups are present in hydroxyquinol?

The total number of isomeric trimethylbenzene is

$A$ compound $X$ formed after heating coke with lime reacts with water to give $Y$,which on passing over red hot iron at $873 \ K$ produces $Z$. The compound $Z$ is:

Toluene on oxidation with dilute $HNO_3$ and alkaline $KMnO_4$ gives:

Identify the product $P$ obtained in the following reaction:
$\text{Benzene} + \text{Ozone (excess)}$ $\xrightarrow{CCl_4} \text{Benzene triozonide}$ $\xrightarrow{Zn/H_2O} P + H_2O_2$

Give the reaction for the formation of $m$-dinitrobenzene from benzene.