Most Common Answer on the ACT: Guess C?

Everyone knows that, when guessing on a multiple-choice test, the best answer to choose is C...right? A friend of a friend swears by it, it’s served you well in the past (maybe?), and it’s become such a commonly known “fact,” such an undisputed strategy, that you may feel as if you were born knowing it—”when in doubt, pick C and move on.”

But does this time-honored tradition of picking C when in doubt actually work on the ACT? And if not, what can you do to improve your odds when guessing? Let’s look at the facts.

Why You Should Answer Every Question on the ACT

First of all, there is no penalty for choosing a wrong answer on the ACT, so make sure to never leave a question blank. You'll earn one point for every correct answer you choose and zero points for any blank or wrong answers, so it doesn't hurt you to make a guess. If you don't know an answer and guess it wrong, you'll earn the same number of points that you would have had you left it blank (zero). And if you guess the question right, you'll earn yourself one point!

Now when you're forced to guess on a question for whatever reason, you'll have to decide between the two main types of guessing: educated guessing and blind guessing.

So let's break down how and when to go about making each type of guess.

Educated Guessing

You can make an educated guess when you: understand the gist of a question, but don't have the time to work through it completely, don't quite know how to work through a question completely, or you're torn between a few answer options. But if you've got some idea of what the answer can (and—just as important—what it can't) be, it's time to eliminate some answer choices and make an educated guess.

For example, let's look at an ACT math problem:

Even if you don't have enough time to completely work through the problem or don't know all the steps, just a little knowledge of lines and slopes will tell us that the answer will be B, C, or D. Why? Because our given slope is -2/3 and a negative slope will fall down towards the right when drawn through our given point (2, 5). This means we can eliminate answer choices A and E immediately.

(Spoiler alert: D is the right answer.)

Blind Guessing

But let's say you've come up against a question and you have absolutely no clue where to begin. Or maybe you've got ten seconds left on the clock and fifteen questions still left unanswered. You know that leaving a question blank is tantamount to throwing your points out the window, so now it's time to make a blind guess. There's no time for educated guessing or eliminating answer choices—you just have to fill in a bubble.

But when you have to make a blind guess like this (or multiple blind guesses), are you better off choosing C than any other answer choice? Let's see.

Don't let their cheerful smiles fool you—three of them are hiding the wrong answer, dun dun DUN.

Fact or Fiction: Is C the Most Common Answer on the ACT?

The idea that C is the best answer to choose when guess-answering a question on a multiple choice test rests on the premise that ACT answer choices are not truly randomized. In other words, the implication is that answer choice C is correct more often than any other answer choice. After all, if the answer key were truly randomized, then why should C be any more likely to be the right answer than any other option?

[Note: the ACT switches between using A, B, C, D (and E on the math section) and F, G, H, J (and K on the math). H is the equivalent to C.]

Some (or even many) of your high school teachers likely still design their tests by hand, which means that their answer keys will not be statistically random. No matter how much your teachers try to randomize their choices, human beings are NOT random and cannot properly randomize a series. For instance, a truly random sampling will actually produce bizarre strings of patterns—e.g., five AB’s in a row, or twenty questions without a D—and most people do not (or cannot) create these patterns when they try their best to be “random.”

Fortunately or unfortunately, this is NOT the case on the ACT. Unlike many of the tests you take in high school, ACT answer keys are completely computer generated. And computers are very good at being random. This means that the answer choices will have a statistically even distribution of 1 in 4 for each answer choice letter (or 1 in 5 on the math section): there is no most common answer on the ACT.

So, ultimately, guessing C (or any letter!) will give you the correct answer only a statistical 25% of the time (20% on the math section). Which means it's NOT true that choosing C will give you a better rate of success than choosing any other letter for your blind guessing.

What to do, then?

So How Should You Guess?

If C isn't the most common answer on the ACT, then which letter should you guess? The truth is that it doesn't matter which letter you pick, only that you stick to the one you choose.

The best strategy, and the one that will maximize your overall point gain, is to pick your favorite letter and fill it in for every blind guess. Maybe that letter is A/F or B/G — it doesn't matter. Just be sure to stick with it every single time.

So definitely go ahead and choose C/H to be your designated letter if you like it best! (Just don't expect C to be any better an answer choice than A, B, or D.)

But maybe you're thinking that sounds completely illogical. Why should you fill in the same letter over and over?

Why Does Sticking to One Letter Increase Your Odds of Guessing the Right Answer?

Your overall score will improve if you stick to choosing the same letter again and again when making blind guesses. This is because people are never truly random. If you’re making "random" blind guesses in a spread, you will almost certainly reduce your overall guesses odds, because your best attempt at random guessing cannot replicate computer-generated randomness.

But by sticking to your designated letter when making blind guesses, you are re-introducing an element of randomness.

Let’s see this in action to better demonstrate why this works.

Scenario: It’s crunch time and you’ve run out of minutes on the clock. You have 15 questions left to go and only a few seconds to bubble in your answers. This means you don’t have time to even look at the questions, so you must try to make the best blind guesses you can and maximize your point-gain.

You are left with two options: make a random guess spread, or fill in every letter with the same answer choice.

Let’s see how each option does when compared to a real ACT answer guide (in this case, we are using the first 15 answers of the 2015/2016 ACT reading section answers, with all F, G, H, J's converted to A, B, C, D's.)

(Note: for our random spread, we tried to guess as randomly as we could without looking at the answer key, and for our consistent letter, we simply went with C.)

By choosing a random spread, we earned 2 points out of a possible 15. But by sticking with one answer choice, we earned 4 points.

Ultimately, sticking to the same letter won't work better for each individual question, but on average and over a spread, the strategy will let you maximize your overall point-gain.

Oh, statistics, you strange creature.

The Take-Aways

So is C the most common answer on the ACT? No! But is it the best letter to choose when you're in a bind and don't know what the right answer choice is? Well, that's more complicated.

Always remember that it's in your best bet to eliminate answer choices whenever possible. But if you can't, and you must make a blind guess, then stick to one letter and run with it every time. If you want this letter to be C (and it's equivalent, H), then go right ahead! Just make sure you stick with it every single time.

C isn't any better or worse than any other letter, or any more likely to be the correct answer, but if you decide to stick with it for every blind guess you make, you'll be better off than trying to be "random."

What's Next?

Blind guessing strategy is great in a pinch, but elimination is always better! Check out our guides on how to make your best guesses on the ACT, how to eliminate answer choices on the ACT math section, and how to avoid the top elimination pitfalls that many students make. 

Want to get more ACT practice? Check out all the free ACT tests available online and gauge how you're scoring by checking out what falls into a "good" and "bad" ACT score.

Want to improve your ACT score by 4 points or more? Check out PrepScholar's test-prep program with our five day free trial.