Number of shared electrons between carbon-carbon atoms in an ethylene molecule is

For the given reaction:
(Cyclohexyl)-$CH$=$CH$-(Cyclohexyl) $\xrightarrow{KMnO_4/H^+}$ '$P$' (major product)
'$P$' is:

$(R)-3-$bromocyclopentene (shown below) reacts with $Br_2/CCl_4$ to form two products,$Y$ and $Z$. $Y$ is not optically active (does not rotate plane-polarized light). What is the structure of $Y$?

The major product of the following reaction is

$CH_3-CHCl-CHCl-CH_3$ $\xrightarrow[dry \ ether]{Na} X$ $\xrightarrow[(1) \ BH_3, THF; (2) \ H_2O_2, OH^-_{(aq)}] Y$; $Y$ is:

The product of the addition reaction of ethene with $Br_2$ is......