# Thread: For all a,b in ℤ/n, can a be divided by b in ℤ/n if, and only if, gcd(n,b) = 1?

1. ## For all a,b in ℤ/n, can a be divided by b in ℤ/n if, and only if, gcd(n,b) = 1?

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2. Originally Posted by feyomi
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No. For example, in $\mathbb{Z}/n\mathbb{Z}\,,\,n\geq 4\,,\,\,2$ divides $4$ since $4=2\cdot 2$

Tonio