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I'm trying to solve this problem which is connected with Group Theory.

As I've already noticed any group of order 224 must be non-simple. How then I should check if it is abelian or not (in general case)?

2 Answers2

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Every group of order $n$ is abelian iff $n$ is a cubefree nilpotent number.

Therefore, not all groups of $224$ can be abelian because $224=2^5 \cdot 7$ is not cubefree.

(You don't even need to known what a nilpotent number is.)

lhf
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  • See http://math.stackexchange.com/a/156492/589 and http://math.stackexchange.com/questions/227628/what-are-the-situations-in-which-any-group-of-order-n-is-abelian – lhf Dec 14 '16 at 10:02
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The dihedral group $D_{112}$ has order $224$ and is not abelian. So it is not true.

We also know that every group of order $224$ is solvable, but this doesn't matter here. Indeed, all dihedral groups are solvable. We only need to find one non-abelian group of order $224$ to refute the claim that all groups of order $224$ are abelian.

Dietrich Burde
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