Index of intersection of subgroups
106927
How do I prove $[G:H\cap K]\leq [G:H][G:K]$?
48273
If a maximal subgroup is normal, it has prime index
53409
Show group of order $4n + 2$ has a subgroup of index 2.
42449
Is there any efficient algorithm for finding subgroups of a given finite group?
106756
Union and Intersection of Sets $A_{i}$ and $B_{j}$
122335
Abelian $p$-group with unique subgroup of index $p$
74077
A intersection (A union B)
64408
Subgroup of $\mathbb{Q}$ with finite index
70538
Intersection and union of simply connected domain
108049
Determining the number of subgroups of $\Bbb Z_{14} \oplus \Bbb Z_{6}$
74796
Extension of intersection of ideals
144582
Index of a subgroup in $SL_2(\mathbb{Z})$
48397
Index of a sublattice in a lattice and a homomorphism between them
51747
Showing that the intersection of all subgroups of order $n$ is normal
130156
Image of the union and intersection of sets.
151210
How can we find and categorize the subgroups of $\mathbb{R}$?
62180
Best way to find the intersection of multiple sets?