This is the exercise 2.18 from Introduction to Bioalgoritms of Neil Jones. It says:
We have a mix of 100 participants: some are honest while others are not. The honest ones always tell the truth, but the deceitful ones sometimes tell the truth and sometimes lie. You can ask any participant the following question about any other participant: “Participant Y, is Participant X honest?” Participant Y will answer with either “yes”or “no.” Design an algorithm that, with no more than 198 questions, would allow you to figure out which of the 100 participants are honest. It is known that there are more honest than dishonest participants.