Question

$a\equiv b\left(modn\right)$ means .

• A. a+b divisible by n
• B. a-b divisible by n
• C. a divisible by n

Answer 1

The correct option is B a-b divisible by n

Two integers $a$ and $b$ are congruent modulo $n,$ if they differ by an integer multiple of $n.$
This can be represented as $a\equiv b\left(modn\right),$which means that $a-b$ is divisible by $n.$