In which of the following,addition of $HBr$ does not take place against Markownikoff's rule,or for which is the Anti-Markownikoff addition of $HBr$ not observed?

The major product $(P)$ formed in the below reaction is:
$CH_2$ attached to a cyclohexane ring $\xrightarrow[(ii) NaBH_4, OH^-]{(i) Hg(OAc)_2, H_2O-THF} P?$

What will be the major product of each of the two reactions shown below?
$1.$ $CH_3-CH_2-CH(N^{+}(CH_3)_3)OH^{-} \xrightarrow{\text{heat}} CH_3-CH=CH-CH_3 (X) + CH_3-CH_2-CH=CH_2 (Y)$
$2.$ $CH_3-CH_2-CH(Br)-CH_3 \xrightarrow{\text{heat}} CH_3-CH=CH-CH_3 (X) + CH_3-CH_2-CH=CH_2 (Y)$

Predict the major product for the following reaction:
$CH_2=CH-CH_2-I \xrightarrow{HI \text{ (Excess)}} ?$

Predict the major product $A$ for the following reaction:
$2\text{-methylbuta-1,3-diene} + HBr (1 \text{ eq.}) \xrightarrow{-80^{\circ}C (1,2\text{-addition})} A$

Which alkene is formed from the following reaction: $CH_3-CH_2-CH_2-CH=PPh_3 + CH_3-CO-CH_2-CH_3$?