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ehrenfest
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[SOLVED] Larson 4.4.13
A is a subset of a finite group G, and A contains more than one-half of the elements of G. Prove that each element of G is the product of two elements of A.
Is that even true? What if G is just the union of the cyclic group with 20 elements and the cyclic group with 21 elements. Let A = C_21. ord(G) = 20+21-1=40. A has more than half of the elements of G but you cannot get any elements of the C_20 subgroup except the identity with a product of elements of the C_12 subgroup.
Homework Statement
A is a subset of a finite group G, and A contains more than one-half of the elements of G. Prove that each element of G is the product of two elements of A.
Homework Equations
The Attempt at a Solution
Is that even true? What if G is just the union of the cyclic group with 20 elements and the cyclic group with 21 elements. Let A = C_21. ord(G) = 20+21-1=40. A has more than half of the elements of G but you cannot get any elements of the C_20 subgroup except the identity with a product of elements of the C_12 subgroup.