Let \(G\) be a group of order \(1575\). Prove that if \(H\) is a normal subgroup of order 9 in \(G\), then \(H \le Z(G)\).

Show that if \(|G| =pqr\) , where \(p,q,r\) are distinct primes, then \(G\) is not simple.

If a group of order \(p^n\) , where \(p\) is a prime, contains exactly one subgroup each of orders \(p,p^2, \cdots ,p^{n-1}\) , prove that it is cyclic.

Let \(G\) be a group. Prove that \(|G/Z(G)| \neq 77\) .

If \(G\) is a group with \(|G|=p^n\) , where \(p\) is a prime, and if \(0 \le k \le n\) , show that \(G\) contains a normal subgroup of order \(p^k\)  .

Let \(H\) be a proper subgroup of a finite p-group \(G\) . If \(H=p^s\) , then prove that there is a subgroup of \(G\) order \(p^{s+1}\) containing \(H\) .

Prove that a finite p-group cannot be simple unless it has order p

Let G be a finite group and p a prime. Show that a normal p-subgroup of G is contained in every Sylow p-subgroup of G.

If \(P\) is a normal Sylow p-subgroup of \(G\) and \(H \le G\), prove that \(P \cap H\) is a unique Sylow p-subgroup of \(H\).

Let \(H\) be a subgroup of a finite group \(G\) and \(p\) a prime. Prove that \(|Syl_p(H)\ \le |Syl_p(G)|\) .

If \(G\) is a finite group and \(p \in Syl_p(G)\), show that \(N_G(N_G(P))=N_G(P)\) .