Group Theory and Lagrange's Theorem: coprime subgroups.
141683
$ |G_1 |$ and $|G_2 | $ are coprime. Show that $K = H_1 \times H_2$
103002
Group equals union of two subgroups
90511
Commutator subgroup of a dihedral group.
22444
Normal subgroups of dihedral groups
131516
Subgroup generated by n-th powers of elements
111375
Normality of subgroups and Sylow groups under homomorphisms...
129830
A group with no proper non-trivial subgroups
41695
Conjugate class in the dihedral group
111049
Groups with given automorphism groups
80381
Groups with "few" subgroups
113840
Does converse of Lagrange's theorem hold for a group of order 21?
30236
isomorphic groups related in direct product.
123699
Schur multiplier as a subgroup in finite abelian groups.
86336
For $G$ group and $H$ subgroup of finite index, prove that $N \subset H$ normal subgroup of $G$ of finite index exists
88344
Order of a group and subsequent subgroups
142938
Sylow 2-subgroups of the group $\mathrm{PSL}(2,q)$
41231
Subgroups of (Z,+) of order n