Question: Why do both Dan Akroyd and Chevy Chase get in trouble for cheating on the exam (since Chevy is quite obviously the only one cheating)?
Question: Dan Aykroyd tricks the Russians into revealing themselves by saying something in Russian. What does he say specifically?
Answer: According to the IMDb trivia for the film, it's "Чем меньше знаешь, тем лучше." ("Chem men'she znaesh', tem loocheh."), meaning "The less you know, the better."
Answer: Dan Akroyd was giving Chevy Chase the answers to the test, KGB was one of them.
JamesP