$CH_3-CH=CH-CH=CH_2 \xrightarrow[Zn]{O_3 / H_2O}$ Which will not form?

Find out the major product of the following reaction:
$2 \text{ mole } CH_2=CH-CH_2Br \xrightarrow{Mg, T.H.F.} \text{?}$

What is the major product of the following reaction?
$1\text{-methylcyclohexene} + Br_2 \xrightarrow{H_2O} ?$

Addition of $HCl$ to $3,3$-dimethyl-$1$-butene yields two products,one of which has a rearranged carbon skeleton. Among the following carbocations,select the possible intermediates in that reaction:
$1.$ $(CH_3)_3C-C^+H-CH_3$
$2.$ $(CH_3)_3C-CH_2-C^+H_2$
$3.$ $(CH_3)_2C(Cl)-C^+(CH_3)_2$
$4.$ $(CH_3)_2C^+-CH(CH_3)_2$

$Isobutylene$ $\xrightarrow[(2) H_2O]{(1) O_3}$ $Product$

The reaction of $HBr$ with the following compound would produce: