C{{H}_{2}}+HBr\xrightarrow{\text{peroxide}}\] \[\underset{n-\text{propyl}\,\text{bromide}}{\mathop{C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-B}}\,r\] In presence of peroxide ADDITION takes place according to Anti Markownikoff?s RULE and hydrogen atom goes to that CARBON atom which is less hydrogenated.