Question

Simple Discrete Mathematics Problem:

You meet two people: person A and person B. You know that they can either be truth tellers or liars. Determine what person A and person B are based on what they say:

A: Only one of us is a truth teller
B: Math is fun.

Answer 1

Oh this is the same question lgba asked a year ago :3

Answer 2

Is it a paradox?

Answer 3

paradox? i would like to avoid that as much as possible

Answer 4

there is a discrete answer to this though

Answer 5

and it is very true if i do say so myself

Answer 6

@uri yes. it is my dream that by reviving these challenging questions, one day old users would come back and so more askers would also join. I believe in an OpenStudy utopia

Answer 7

person A speaks the truth, and person B lies

there are 4 possible outcomes: Lie,Lie , Lie,Truth , Truth,Lie , Truth,Truth

1. if both Lie, that means statement "Only one of us is a truth teller" is a lie and not only one, but both of us speak the truth. however, this is impossible hence we already determined person A speaks Lies

2. same thing happens if person A lies and B speaks the truth. again, not possible because we started with the assumption that person A is lying.

3. this scenario is possible, because if person A speaks the truth, then "Only one of us is a truth teller" is a true statement, and person A is that person. person B is the second and person B lies.

4. not possible, because if person A tells the truth then the statement "Only one of us is a truth teller" should be truth, and if person B speaks also the truth, the statement obviously is a lie. contradiction.

Answer 8

so math is not fun eh? i agree...

Answer 9

Math sucks

Answer 10

yes. yes it does