Answer
The major product is shown in the picture. It is 1,2-dibromo-1-methylcyclopentane.
Work Step by Step
$Br_2$ adds two Br across the double bond. First one Br adds across the double bond and forms the bromonium ion. The bridge formed blocks one surface. Thus, the next Br ion has to attack from the other side, giving trans addition of Bromines.
