What To Do When You have No Idea Which Answer Is Correct

Written and edited by the MCAT Self Prep Tutoring Team

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What do the AAMC and Sandy Koufax have in common? They LOVE a good curveball. No matter how prepared you are to take the MCAT, you will almost certainly encounter questions that you have no clue how to answer (I know I did!). Here’s what to do when you encounter an IHNC (“I have no clue”) question!

Don’t Panic!

Trust your preparation, and remember that no single question is going to determine whether you go on to become a successful doctor! If a specific answer seems correct, it could be because you remember that information subconsciously from your content review.

Know Your Strategy

I strongly encourage you to account for IHNC questions as part of your timing strategy. It’s important to determine your plan well in advance of test day for two reasons:

  1. You don’t want to spend precious time and energy on test day trying to budget your time on the fly.
  2. It’s much easier to make rational, objective timing decisions when you’re planning your strategy than on test day.

When you’re deciding on your IHNC strategy, I suggest considering a few questions:

  1. What’s the maximum amount of time you will allow yourself for an individual question? The answer to this question may be different for each section, and you may also want to move on more quickly from discrete questions than from passage-based questions. 
  2. Do you intend to mark IHNC questions and revisit them at the end of the section, or do you only plan to take one pass? If you don’t intend to come back, you may want to allow yourself slightly more time on your first pass.

As an example, I found that revisiting challenging questions was a very successful strategy for me, so if I didn’t know how to answer a question within about 45 seconds, I would make an educated guess, mark the question for review, and move on. I do NOT mean I would finish solving every question within 45 seconds, just that I would move on if I couldn’t figure out where to start within that time. I would then aim to revisit all of my marked questions at the end of the section. Conversely, you may decide that if you are going to spend 2 minutes on these difficult questions, you may have the best shot at getting it right if you don’t break up your concentration in between. 

Of course, as always, it’s up to you to experiment and decide what works best for you!

Pay Attention to Units!

Units are your best friend for IHNC science questions, especially those that are calculation-based. They can help you determine:

  1. Which part of the passage is relevant to the question. If you’re not sure how a particular question stem or answer choice relates to the passage, you can often use units to help guide you. For example, if a question asks you at which pH you might expect a particular observation, and the passage includes a graph of some variable vs. pH, that’s probably a good place to start!
  2. How to perform a calculation. You may encounter questions that ask you to perform unfamiliar calculations. In this case, you may be able to use the units in the answer choices, combined with the units in the information you’re given, to reverse-engineer the formula. For example, say you’re asked to calculate the impulse an object experiences in a collision given the average force exerted on it, and the duration over with the force is applied. You remember that impulse is equal to the change in momentum, but you can’t remember how to calculate it. You can reason that a change in momentum must have the same units as momentum itself (kg * m/s), and since the question gives you a force (in N, which are equal to k * m/s2) and a duration (in seconds), you can recognize that you multiplying force by duration yields a result in kg * m/s, which is exactly what you need!
  3. What a particular variable is measuring. The AAMC loves to bury surface-level content in layers of misdirection. Units can help you cut through the noise! 

I encourage you to pay close attention to units during your content review. A great goal would be to:

  1. Know the SI name for each unit and what it measures. For example, know that kilograms measure mass, Watts measure power, and so on.
  2. Be able to express each compound SI unit in terms of base units. This is incredibly important because it allows you to create physics equations if you forget them. For example, know (or feel comfortable quickly deriving) that a Watt = J/s = kg*m2/s3.
  3. Be able to articulate in plain language what a particular quantity represents. For example, know that power (measured in watts) is a rate of energy transfer.

Find a Common Denominator

The AAMC loves elaborate experimental methods, which can make it much more challenging to reason about the relationships between variables and outcomes. If you’re stuck on a particular question because you’re not sure how to relate the question stem, answer choices, and/or passage, you may want to step back and try to express them in common terms.

For example, suppose a particular passage discusses a series of experiments about microtubules, but the question on which you’re stuck asks about amoeboid movement. It may be helpful to recognize that amoeboid movement is a specific case of microtubule polymerization and depolymerization, so you can think of amoeboid movement as simply a proxy for microtubule activity. You can then rephrase the question and answer choices by replacing “amoeboid movement” with “addition or removal of actin units from microtubules”. Once the passage, question, and answers are all in the same terms, you may find the question is easier to solve!

Compare and Contrast the Answer Choices

Even if you have no idea what a question stem is asking nor how the answer choices address the question, you may still be able to arrive at the correct answer just by finding similarities or differences between the answer choices. A few questions to ask yourself:

  1. How are the answer choices similar or different from one another? For example, maybe all the answer choices are involved in glycolysis, but only two catalyze irreversible reactions. Could that distinction be relevant? Instead of focusing on small differences in word choice, focus instead on the biggest difference between the answer choices that you’re evaluating. What concept does each answer choice represent? Why did the AAMC include them?
  2. Is one answer choice different from the other three in some way? For example, say the answer choices are all amino acids, and only one is commonly phosphorylated. If you can make a case to yourself that phosphorylation is relevant to the question, then you may have found the correct answer!
  3. Are any of the answer choices logically equivalent/consistent? Since only one answer choice can be correct, if two or more answers are logically equivalent (e.g. if one is true, then the other must also be true), then none of them can be correct. So you can eliminate them! Similarly, if one answer choice is a subset of another answer choice (Is the author’s favorite food pizza or a form of Italian food?) you can always eliminate the subset answer choice. In the food example, if the author’s favorite food was pizza, the author’s favorite food would also be a form of Italian food. We can’t have two correct answers and therefore pizza won’t be correct.
  4. Are any of the answer choices mutually exclusive? If two answer choices cannot both be true or both be false, then it’s likely that one of them is the correct answer. In this case, you may be able to eliminate the other two choices.

You can also use any of these strategies to help understand what an IHNC question is asking—if you can identify how the logic varies among the answer choices, you may be able to reverse-engineer what the question is asking!

Use Process of Elimination

If all else fails, you can always use process of elimination to remove as many answer choices as possible and then make a guess. A few useful heuristics:

  1. If ANY part of the answer choice is incorrect, or even suspect, throw it out. The AAMC loves to use distractors that are almost completely correct but have one inaccuracy. Be ruthless.
  2. If you can’t relate an answer choice to the passage, throw it out. If you truly have no clue how to answer a particular question, discard any answer choices that you don’t think relate to the passage.
  3. If an answer choice doesn’t make sense, throw it out. The AAMC deliberately throws in lots of nonsense answer choices. Trust your preparation, and feel confident that if an answer choice feels ridiculous, it probably is. Throw it out, and thank the AAMC for the freebie!

Important disclaimer: strategies two and three truly are last resorts. Be careful about using them, because they are certainly NOT perfect (though likely better than a blind guess).

Be Careful with CARS…

IHNC questions in the CARS section are a little bit trickier, and require some special considerations:

  1. Pay attention to whose views are relevant to the question. The AAMC often chooses passages that present several different viewpoints, so double-check that you understand whose perspective is relevant to the question, and eliminate answer choices that do not represent that person’s view. For more information on this topic, check out the CARS Strategy course!
  2. Be VERY judicious about revisiting the passage. I would encourage you to go back to the passage only if you know exactly which sentence(s) you’re looking for, where it is in the passage, and how the information you find will inform your answer.
  3. Use the main idea and tone for process of elimination. Some incorrect answer choices are recognizable because they are not consistent with the main idea and/or tone of the passage. Discard these choices.

Remember that everyone (E-V-E-R-Y-O-N-E) sees questions they don’t know how to answer on the MCAT, so don’t be discouraged. You’re competent and capable, and you’re doing all the right things to achieve your MCAT goals!

Warm Regards,


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Alex scored a 528 after self-prepping for his exam as a non-traditional student working at Google. After spending years helping students overcome challenges on many standardized exams, he’s ready to help you with any MCAT challenges you face! You can learn more and sign up to work with him one-on-one here.

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