Should you answer all of the SAT questions?

No, you should not necessarily answer all of the SAT questions. It's far better to answer the questions you know how to do correctly and strategically skip the ones you're unsure of. There's a penalty for incorrect answers (specifically, a quarter of a point is deducted from your raw score for each incorrect multiple-choice answer). Therefore, randomly guessing on many questions can actually lower your score. It's more beneficial to focus your time and energy on the questions you can confidently answer.