What is the major product formed when $3$-phenylpropene reacts with $HBr$?

Which reagents shown below would accomplish the following transformation?
$Isopropyl \ bromide \xrightarrow{1. A \ 2. B} Isopropyl \ alcohol$

Predict the correct reactivity order of the following compounds towards $S_N1$ reaction:

Arrange the compounds of each set in order of reactivity towards $S_{N}2$ displacement:
$(i)$ $2-Bromo-2-methylbutane$,$1-Bromopentane$,$2-Bromopentane$
$(ii)$ $1-Bromo-3-methylbutane$,$2-Bromo-2-methylbutane$,$2-Bromo-3-methylbutane$
$(iii)$ $1-Bromobutane$,$1-Bromo-2,2-dimethylpropane$,$1-Bromo-2-methylbutane$,$1-Bromo-3-methylbutane$.

An alkyl bromide $(X)$ reacts with sodium in ether to form $4,5-$diethyl octane. The compound $X$ is:

The following compound on hydrolysis in aqueous acetone will give: