The maximum number of possible isomers (including stereoisomers) which may be formed on mono-bromination of $1$-methylcyclohex- $1$-ene using ${\mathrm{Br}}_2$ and $\mathrm{UV}$ light is ___.

In the reaction scheme shown below, $\mathrm{Q}, \mathrm{R},$ and $\mathrm{S}$ are the major products.

 The correct structure of 

The correct statement(s) for the following addition reactions is(are)