Proving Denumerability of Positive Multiples of Three Greater Than 100

[eibon]

Homework Statement

Let S be the set of positive multiples of three which are greater than one hundred.
Show that S is denumerable.

Homework Equations

The Attempt at a Solution

let $$\phi$$: $$N$$ $$\rightarrow$$ S
be given by $$\phi$$(n)= 99+3n is a bijection
thus it is denumerable

can someone tell me if that is right? if not can you tell me what i did wrong?

 

[Dick]

Why would you think it's not right? It is.

 

[eibon]

well its the first time I am taking an math class like this and I am just not sure if I am doing things right

 

[Dick]

well its the first time I am taking an math class like this and I am just not sure if I am doing things right

Well, you are doing it right.

 

[eibon]

Thanks for the reassurance