Answer
First ethylene reacts with HBr to form Ethyl Bromide:
$C_{2}H_{4} + HBr → C_{2}H_{5}Br$
After that ethyl bromide reacts with Benzene to form Ethyl Benzene
$C_{6}H_{6} + C_{2}H_{5}Br → C_{6}H_{5}C_{2}H_{5} + HBr$
Work Step by Step
Given above
