Question

What happens when bromine attacks ch2=ch-ch2-c=ch?

Answer 1

The reaction of Bromide depends on how much bromide you have.

With enough bromide it is possible to get CH2Br-CHBr-CH2-CBr2-CHBr2.

Both double and triple bonds can get brominated.

 But if there are limited amount of bromide, then double bonds react with bromide faster than triple ones forming mainly CH2Br-CHBr-CH2-CCH but also CH2=CH-CH2-CBr=CHBr.