Major product P of above reaction, is:

First reaction is addition of HBr in presence of peroxide which takes place according to anti-markonikov's rule.

The synthesis of alkyl fluorides is best accomplished by heating an alkyl chloride/bromide in the presence of a metallic fluoride such as AgF, Hg₂F₂, CoF₂ or SbF₃. The reaction is termed as Swarts reaction.

$$H_3C-Br + AgF \longrightarrow H_3C-F + AgBr$$, however this does not effect the bromine directly attached to the benzene ring.