What are the elements of the subgroups <3> and <15> in Z(18)?

[Benzoate]

Homework Statement

List the elements of the subgroups <3> abd <15> in Z(18)

Homework Equations

The Attempt at a Solution

<3>={0,3,6,9,12,15} .
<15> ={0,15}

Together , I can conclude that the number of elements amongst <3> and <15> add up to 7 elements.

 

[NateTG]

It's all correct, although I'm not sure that:

Together , I can conclude that the number of elements amongst <3> and <15> add up to 7 elements.

Is all that interesting.

 

[learningphysics]

<15> ={0,15}

<15> has more elements than that.