# Thread: waht is ?

1. ## waht is ?

what is the GCD of n and n+1

2. ## Reply

It is $1$, obviously ... can $n + 1$ possibly divide $n$ ? No. You can investigate this fraction :

$\frac{\ n + 1}{n}$

And saying that two consecutive numbers have a common factor (except 1) is saying that :

$(n + 1) mod n = 0$

Which is impossible.