I did the first seven homeworks, and ended up with like an 18% average, but over the same timespan, got multiple 80%+ on quizzes and a 101 on the test. So clearly, the homework did nothing. I stopped doing it because I couldn't get above the 50, so it was a waste of time. I told him this, and he claimed he asked many times if people were having trouble with the homework (he didn't). And then he said he had to leave.