Exercise · ZW-BURNSIDE-S-LEMMA-004 · ★☆☆ Basic

If \(|G| = 6\) and the sum of fixed points is 18, how many orbits are there?

Choose one option.

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  • B. 3

Explanation

Dividing the sum 18 by the group size 6 gives 3 orbits.

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Review the concept: Burnside's lemma

Burnside's lemma (also called the Cauchy-Frobenius lemma) states that the number of orbits of a finite group G acting on a set X equals the average number of fixed points of the elements of G.

\[|X/G| = \frac{1}{|G|}\sum_{g\in G}|X^g|\]

More practice problems: burnside's lemma

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