<p>Last year my friend said that Pang’s 20L tests were all conceptual with absolutely no math involved. I saw his 2007 midterm and it was 90% math. He is probably trying to make his tests as unpredictable as possible so don’t relay on his “study guide” unless if you have the other professor. I took 20L in W09 with a different professor and her midterm was all math, while her final was pretty balanced between math and conceptual questions.</p>