There are simply not enough worked examples of compound inequalities to prepare for multiple choice Q&A even someone who is refreshing themself on the subject. Please, provide more worked examples which resemble more closely the more varied outcomes encountered in the exercise, perhaps a preparatory worksheet within the unit. The basics are good for establishing a fundamental understanding, but not enough to bridge the gap between the lesson and the exercise. And the most important part is to provide easy-to-remember restrictions & guidelines (rules) to selecting a correct single choice/solution(s). Thank you, and thank you so much for what you are doing at Khan Academy.