Is this a mathematics problem?

[madah12]

Homework Statement

In a group of nine people some are always telling the truth and some
are always lying. Some of them are sitting around a round table. They all claim
that their neighbor on the right is a liar. How many people are sitting around the
table?

Homework Equations

The Attempt at a Solution

I am not that interested in solving it but I am curious if it can be solved with mathematics and what field of mathematics does it fall into?

 

[╔(σ_σ)╝]

Discrete math; specifical logic.