The Data Insights section of the GMAT Focus imposes such significant time constraints that test takers must find ways to make up time, but most of the question types present so much information to be processed that it can be very difficult to find ways to move quickly. Enter Data Sufficiency! Though one MUST be careful on these questions (more on that below), Data Sufficiency questions present the best opportunity to move quickly.
The NEW Data Sufficiency and the NEW Data Insights Section
Before we get into the details of this, it’s worth first pointing out how much of a departure this is from the previous version of the GMAT (when Data Sufficiency was part of the Quantitative section of the test). One of the primary mistakes that people tended to make on that version of the exam was to move TOO quickly through Data Sufficiency. They would “go on a hunch” too often and fail to “prove” what they thought to be true. Literally, that was the number one “problem” that we would have to address with people in the past here at RTP. And it’s still an issue. But now DS is much more of a balancing act: should you accept the conceptual hunch that you have in the interest of saving time or should you go further and prove what you believe to be true? The answer is that it depends on a bunch of factors, but more often than in the past, test takers need to seize the opportunity to save time on Data Sufficiency when possible and make some educated guesses.
The Problem with the “Other” Data Insights Questions
In our experience with the Data Insights, we have found that test takers really struggle to finish this section. The problem is that all of the question types, apart from Data Sufficiency, present a lot of information, either written or graphical, that is just difficult to get through quickly. People read and process such information at a particular speed, and trying to digest the information more quickly than you are comfortable doing so is not advisable. By the time you have read the information and processed the graphs/tables, if any, it makes sense to just finish up the question to the best of your ability. Sure, if you’re stuck on one of the questions you should pick an answer and move on, but it’s very difficult to answer any of the non-Data Sufficiency Data Insights questions quickly.
Saving Time on Data Sufficiency
But data sufficiency is different. There are many questions in which it is possible to narrow it down to two answers pretty quickly. For example, it’s often pretty obvious that the statements are not sufficient individually and that they must be combined. That limits the answers to C or E. Additionally, it is sometimes clear that one of the remaining two answers is a bit of a trap and that the other answer is much more likely. In cases such as these, one might be better off just picking that more likely answer and moving on. Altogether, a situation like the above might cost a test-taker 30 to 45 seconds. It’s very difficult to be that fast on any of the other Data Insights question types.
Consider the below example:
Theater M has 25 rows with 27 seats in each row. How many of the seats were occupied during a certain show?
(1) During the show, there was an average (arithmetic mean) of 10 unoccupied seats per row for the front 20 rows.
(2) During the show, there was an average (arithmetic mean) of 20 unoccupied seats per row for the back 15 rows.
It should be clear very quickly that the statements are not sufficient individually. The difficult part of this question is determining whether they are sufficient together. But, depending on how you go about it, it might take a long time to prove it, one way or the other. Additionally, you might get the sense that, because there is an overlap in the rows, it might matter where the unoccupied seats are (mostly in the rows that overlap or mostly in the ones that don’t?). Therefore, on a hunch, it might be worth picking E here and just moving on. Don’t be mistaken. Time permitting, it’s always a good idea to prove what you believe to be true on Data Sufficiency questions. But if you are someone who is struggling with time on the Data Insights section, then making some educated guesses, especially in situations where you believe that you are likely to be right, might be a strategy that you need to apply.
A Crucial Factor: The Ability to Review and Change Answers on Data Insights
There is one factor that has not yet been mentioned that makes this strategy all the more important and viable: on the GMAT, you can go back to questions and change your answer! Let’s get the fine print out of the way first, here: you can only change your answer to 3 questions and you can’t go back to questions until you reach the end of the section. But in practice, you probably wouldn’t want to do otherwise anyway, so these “restrictions” are not really restrictions. The ability to review and change your answers is really a game-changer, if you use the ability to your advantage. It might be difficult to get yourself to make an educated guess on a Data Sufficiency question if you are worried that you are going to get the question wrong and fearful that doing so would ruin your score, but if you have the mentality that you are just logging an initial guess and that you could always change it in the end, then it’s easier to move quickly in the cases where it is possible to do so.
Data Sufficiency: Balancing Timing and Clarity
On Data Sufficiency, one really needs to balance timing with certainty. To repeat, we are NOT suggesting that test-takers guess willy-nilly on Data Sufficiency questions. There is an art to knowing when to make an educated guess and when to push further. The essence of that decision is a judgment about how certain you are and how long it would take to increase that level of certainty. If you are 80% sure in your answer and expect that it will take 2 minutes to become more certain, you should probably guess (remember, you can always come back in the end anyway!). If, on the other hand, you don’t even have it down to a 50/50 shot and you expect that if you spend another minute you’ll be able to reach a high degree of certainty, you should spend that time.
Practicing Efficiency on Data Sufficiency to Increase Speed on Data Insights
To zoom out, the key understanding is this: the Data Insights section is a real time-crunch for most people and Data Sufficiency presents the easiest way to shave time off that section. There are separate strategies for the other Data Insights question types that may help to reduce the time one spends on the section, but nothing that really approaches what can be done with Data Sufficiency.
Therefore, as you practice Data Sufficiency, you should think about how you can be more efficient. And to do this, you don’t need to sacrifice thoroughness. At a certain point in your process as you work through a question, you could say, “at this point if I were to guess, I am 90% sure that the answer is C.” BUT, and this is the key, without checking to see if that is the correct answer, you could continue and try to prove out your hunch. In doing so you will get a good side-by-side comparison of the two approaches and start to learn which is better in particular situations. In some cases you will find that it would not have been worth the additional time that you spent, whereas in other cases you will realize that your level of certainty was not high enough and that proving your hunch was necessary. This is how you master the art of time management on Data Sufficiency!