A lecturer enters a class and asks, "where did we stop last week?". Some of the students raised their hands whiles others didn't. So he said, "those of you who raised your hands should tell the rest where we stopped, and he left the class without teaching that day. The students now decided to all raise their hands the next time he comes to ask to impress him. So the next day, He asked the same question and all the students raised their hands. He said "wow! since everyone knows, you guys are brilliant. There's no point teaching you again and he left. The confused students now decided to not raise their hands when he comes the next day so he can teach them. The next day came and he asked the same question, "where did we stop last week?". This time, no one raised their hands. He looked at them for a while and said since no one remembers, it's because no one is taking the class serious so there's no point teaching them again. And he left the class. Now my question is, how can the students make this lecturer teach them? What possible ways can they persuade him?