# Math Help - Help with Equivalence Relations

1. ## Help with Equivalence Relations

Here is my problem,

Let A be a set of all numbers divisible by 3. Show that A is equipotent to B. Important: When you find the bijection from A to Z (all integers) you need to prove it is a bijection.

2. Originally Posted by Nach1855
Let A be a set of all numbers divisible by 3. Show that A is equipotent to B. Important: When you find the bijection from A to Z (all integers) you need to prove it is a bijection.
From the given $A=\{3j:j\in \mathbb{Z}\}~~$. Define $\Phi:A\to \mathbb{Z}$ by $3j\mapsto j$.