Number of $\pi$ electrons present in naphthalene is

The total number of compounds from the list below that,when treated with hot $KMnO_4$,yield benzoic acid is:

The number of $\sigma$ and $\pi$ bonds in a molecule of benzene is

Which of the following compounds is most reactive to an aqueous solution of sodium carbonate $?$ (The structures correspond to cyclic hydrocarbons with varying degrees of unsaturation).

Consider the following reaction sequence:
Vinylbenzene $\xrightarrow[\Delta]{KMnO_4+KOH} X$ $\xrightarrow[\Delta]{NaOH+CaO} Y$
'$Y$' can also be formed from:

Which of the following is anti-aromatic?