Commutativity degree of Zp Zp^n

For a nite group G the commutativity degree denote by d(G) and defind: d(G) =|{(x,y)| x,y G, xy=yx}| \ |G|^2 . In [2] authors found commutativity degree for some groups,in this paper we find commutativity degree for a class of groups that have high nilpontencies.