An alkene $X\left(\mathrm{C}_4 \mathrm{H}_8\right)$ on reaction with HBr gave $Y\left(\mathrm{C}_4 \mathrm{H}_9 \mathrm{Br}\right)$. Reaction of $Y$ with benzene in the presence of anhydrous $\mathrm{AlCl}_3$ gave Z which is resistant to oxidation with $\mathrm{KMnO}_4-\mathrm{KOH}$. What are $X, Y, Z$ respectively?

An alkene $X\left(\mathrm{C}_4 \mathrm{H}_8\right)$ does not exhibit cis-trans is memerisn Reaction of $X$ with $\mathrm{Br}_2$ in the presence of UV light gane $Y$. What is $Y$ ?

What are $X$ and $Y$ respectively in the following reaction sequence?

$$ \text { Isopentane } \xrightarrow{\mathrm{KMnO}_4} X \xrightarrow{\text { Dehydration }} Y \text { Major } $$