Subgroup of a given index
123394
A problem from Isaacs' FGT
88262
How to enumerate subgroups of each order of $S_4$ by hand
54082
Group with exactly two subgroups of index 2
97928
Normal subgroup of a normal subgroup
80381
Groups with "few" subgroups
156941
Subgroups of $\mathbb{Z}$
133770
Subgroups of finite abelian groups.
43750
Subgroups of finite solvable groups. Solvable?
42449
Is there any efficient algorithm for finding subgroups of a given finite group?
121587
Let $H$ be a normal subgroup of index $n$ in a group $G$. Show that for all $g \in G, g^n \in H$
58914
Any group of index 2 is normal
74044
Find all subgroups of $\mathbb{Z}\times\mathbb{Z}$.
154398
Show that H is a subgroup of G
94999
A subgroup with an index of 2 is normal to the group.
91966
Find all subgroups of group
7108
Normal subgroup of prime index
75568
Subgroup of index $2$ is Normal