‎Let $G$ be a finite group and $nu(G)$ denote the number of conjugacy classes of non-normal subgroups of $G$‎. ‎In this paper‎, ‎all nilpotent groups $G$ with $nu(G)=3$ are classified‎.  

Another way to do this is to use individual elements. Take an element from {2, 6} and an element from {3, 7} and add them. Find the coset that contains the sum. That coset is the sum of the cosets. For example, if I use 6 from {2, 6} and 3 from {3, 7}, I get 6 + 3 = 1, which is in {1, 5}. Therefore, {2, 6}+ {3, 7} = {1, 5}. What happens if you choose different elements? Take 2 from {2, 6} and 7...

We study some properties of interval-valued fuzzy normal subgroups of a group. In particular, we obtain two characterizations of interval-valued fuzzy normal subgroups. Moreover, we introduce the concept of an interval-valued fuzzy coset and obtain several results which are analogous of some basic theorems of group theory.