Answer
First Benzene reacts with ethyl bromide to form ethylbenzene:
$C_{6}H_{6} + C_{2}H_{5}Br → C_{6}H_{5}C_{2}H_{5}$
Then ethylbenzene reacts with Br gas in the presence of AlCl3 (Friedelcraft acylation):
$C_{6}H_{5}C_{2}H_{5} + Br_{2} →$ p-bromoethylbenzene + o-bromoethylbenzene
Work Step by Step
Given above