Answer:
Distilation because they have different boiling points
The 3 isomers of pentane and their normal boiling points are:-
pentane, b.p approx. 36.C
iso pentane, b.p approx. 28.C
neo pentane, b.p approx. 10.C
Those differences in their boiling points make possible them to separate by Distilation.
Hope this will help....