The major product formed is 2 -iodo- 2,3 -dimethylbutane. Steps involved in the reaction are as follows: Step 1 it is electrophilic addition reaction, π-bond of alkene attack H+ion of Hl and form more stable carbocation. Step 2 Formation of more stable 3∘ carbocation take place by 1,2 shifting of Me group. Step 3 Direct addition of I⊖ ion.