Which is most viscous?

How many isomers of $C_5H_{11}OH$ will be primary alcohols?

Compound $(P)$ is

What is the decreasing order of reactivity of $HX$ in the reaction $ROH + HX \to RX + H_2O$?

The product $(C)$ in the below mentioned reaction is:
$CH_3-CH_2-CH_2-Br$ $\xrightarrow[\Delta]{KOH_{(alc)}} A$ $\xrightarrow{HBr} B$ $\xrightarrow[KOH_{(aq)}]{\Delta} C$

For the given reaction,if the final product is a mixture of $C_4H_8Br_2$ isomers,what is the value of $X$ (the number of alkenes formed in the mixture)?