In a small village there are two kinds of people: liars and truthtellers.

Everybody knows everybody and everybody knows as well who is a liar and who’s a truth-teller.

I approach six villagers and pose the same question to each of them:

"How many liars are among you?"

I get six distinct answers (integers, of course) and deduce the true one.

How many liars are in that group?

Liars always lie and truthtellers never do.

(In reply to

re(5): solution by Ady TZIDON)

Well, if you insist, all we need to know is in the statement:

"I get six distinct answers and deduce the true one."

In other words, there are 6 answers, 1 of which is true. So 5 are untrue. So there are 5 liars.

In fact, we don't even need to know what the question was.