Which of the following belong to the same homeologous series ?
`C_(3)H_(8),C_(3)H_(6),C_(4)H_(8),C_(4)H_(6)`

Explanation

All these compounds are hydrocarbons , so all that we have to do is to find out which of them alre alkanes ,alkanes and lakynes .
(i) `C_(3)H_(8) "corresponds to the general formula for alknaes" C_(n)H_(2n+2)(with n=3), "therefore", C_(3)H_(89)` is an alkane.
(ii) `C_(3)H_(6) "and" C_(4)H_(8) "correspond ot the general formula for alkenes" C_(n)H_(2n)` (with n=3 and n=4 respectively)," therefore" , `C_(3)H_(6) "and"C_(4)H_(8)` both alkenes.
(iii)`C_(4)H_(6) "corresponds ot the general formula for alkynes" C_(n)H_(2n-2)(with n=4), " therefore" C_(4)H_(6)` is a alkyne.