Getting N-3, as answer?


#1

Take N=4. P1, P2, P3, P4. If we ask P1 about P2 and it replies “good”, then there are two possibilities, either P1 and P2 are both “good” or both “bad”. If both are “bad”, then count of bad >=1/2 of the total count which is not possible, so both has to be good. So we choose either P1 or P2. On the other hand, if P1 replies with “bad”, we dump both P1 and P2(one of them is good and other one is bad.) and the rest P3 and P4 have to be good(for the constraint #good > 1/2 of the total >=3), so we choose P3 or P4. In this case, we see only 1 question is required. That is (N-3). Can someone tell me where am I wrong?