Surjectivity of ${(\mathbb{Z}/m\mathbb{Z})}^{\times}\rightarrow {(\mathbb{Z}/n\mathbb{Z})}^{\times}$
45991
Why $f\colon \mathbb{Z}_n^\times \to \mathbb{Z}_m^\times$ is surjective?
133083
Injectivity and surjectivity of a recursive function
51334
Does there exist any surjective group homomorphism from $(\mathbb R^* , .)$ onto $(\mathbb Q^* , .)$?
26661
Ring homomorphisms from $\mathbb{Z}_n$ to $\mathbb{Z}_m$
48990
Linear map $f:V\rightarrow V$ injective $\Longleftrightarrow$ surjective
57269
A special bijection between $\mathbb{R}\times \mathbb{R}$ and $\mathbb{R}$
120183
Prove that $S_3\times\mathbb{Z}_2$ is isomorphic to $D_6$
98507
$\text{Aut}(F)$ is isomorphic to the multiplicative group of all $n\times n$ matrices over $\mathbb Z$
45792
Rigorous proof that surjectivity implies injectivity for finite sets
35034
Multiplicative inverses for $Z_n$
21391
Proving Functions are Surjective
16610
Surjectivity of a map from a space to itself
154754
Is $O_n$ isomorphic to $SO_n \times \{\pm I\}$?
109596
Isomorphism from $\mathrm{Aut}(\mathbb{Z}/2\mathbb{Z}\times \mathbb{Z}/2\mathbb{Z})$ to $S_3$
30752
Proof of $(\mathbb{Z}/m\mathbb{Z}) \otimes_\mathbb{Z} (\mathbb{Z} / n \mathbb{Z}) \cong \mathbb{Z}/ \gcd(m,n)\mathbb{Z}$
124847
Is the set of surjective functions from $\mathbb{N}$ to $\mathbb{N}$ uncountable?
138058
Prove that $\mathbb Z_{m}\times\mathbb Z_{n} \cong \mathbb Z_{mn}$ implies $\gcd(m,n)=1$.