Most of the questions on the SAT are multiple choice; all multiple-choice questions have five answer choices, one of which is correct. The questions of each section of the same type are generally ordered by difficulty. However, an important exception exists: Questions that follow the long and short reading passages are organized chronologically, rather than by difficulty. Ten of the questions in one of the math sub-sections are not multiple choice. They instead require the test taker to bubble in a number in a four-column grid.
The questions are weighted equally. For each correct answer, one raw point is added. For each incorrect answer one-fourth of a point is deducted. No points are deducted for incorrect math grid-in questions. This ensures that a student's mathematically expected gain from guessing is zero. The final score is derived from the raw score; the precise conversion chart varies between test administrations.
The SAT therefore recommends only making educated guesses, that is, when the test taker can eliminate at least one answer he or she thinks is wrong. Without eliminating any answers one's probability of answering correctly is 20%. Eliminating one wrong answer increases this probability to 25%; two, a 33.3% probability; three, a 50% probability of choosing the correct answer and thus earning the full point for the question.