LOGIC

Question

A certain country is inhabited only by truth-tellers(people who always tell the truth) and liars(people who always lie).Moreover, the inhabitants will respond only to yes or no questions. A tourist comes to a fork in a road where one branch leads to the capital and other does not. There is no sign indicating which branch to take,but, there is a native standing at the fork. What yes or no question should the tourist ask in order to determine which branch to take? [HINT: Let A stand for "You are a truth-teller" and let B stand for "The left-hand branch leads to the capital".Construct by means of suitable truth table, a statement form involving A and B such that the native's answer to the question as to whether this statement form is true will be yes when and only when B is true]

Answer 1

Ans 1)Is it true that you are a truth teller and the left road leads to the capital or you are a liar and the right road leads to the capital?

       2)If I ask you whether the left road leads to capital, you will say 'yes', won't you?

      3)If I ask the other kind of person whether the right road leads to capital, he will say 'yes' or 'no'?

https://www.youtube.com/watch?v=xlUFkMKSB3Y&list=PL0862D1A947252D20

Here I've given the link. Prof Kamla Krithivasan Mam's videos r just superb. I guess in the second video's beginning she explains the answer precisely. Hope it helps you. :)