What is the relative rate of $S_{N}1$ reaction for $(CH_{3})_{2}CHBr$?

Consider the above chemical reaction. Product $A$ is:

For the following reactions:
$CH_{3}CH_{2}CH_{2}Br + Z^{-} \xrightarrow[substitution]{k_s} CH_{3}CH_{2}CH_{2}Z + Br^{-}$
$CH_{3}CH_{2}CH_{2}Br + Z^{-} \xrightarrow[elimination]{k_e} CH_{3}CH=CH_{2} + HZ + Br^{-}$
where
$Z^{-} = CH_{3}CH_{2}O^{-} (A)$ or $(CH_{3})_{3}CO^{-} (B)$
$k_s$ and $k_e$ are,respectively,the rate constants for the substitution and elimination,and $\mu = \frac{k_s}{k_e}$,the correct option is:

The products $A$ and $B$ formed in the above reactions are

$S_N1$ reactions are generally carried out in which type of solvents?

Which of the following alkyl halides gives the most complex mixture of alkenes in an $E_2$ reaction?