Tag Archives: graduate school

How to Rock Sequences on the GRE

On the GRE, there are two types of sequences to watch out for: arithmetic, and geometric. An arithmetic sequence occurs when there is a constant difference between terms. For example, in a sequence of 3, 5, 7, 9…, then the difference is +2. In a geometric sequence, there is a constant ratio and not a constant difference.

The common ratio is found by dividing the 1st term into the 2nd term. For example, in a sequence of 2, 4, 8, 16…, the ratio is 2, since each term is multiplied by 2 to get the next term.

The concept of sequences is fairly simple, but what to do when a question asks for an impossibly high term, such as the 149th term? There isn’t enough time to write the sequence out that far, so we’d use one of the following formulas:

For Arithmetic: an = a1 + (n – 1)d

For Geometric: an = a1 * r(n-1)

In these equations, an = nth term, a1 = first term in the sequence, d = difference, r = ratio, and n = the number of the term you want to find. For example, if we were asked to find the 33rd term in the geometric sequence above, we would plug in as follows:

an = 2 * 2(33 – 1)
an = 233

Let’s look at a practice question:

1. In the sequence of numbers, a1, a2, a3, a4, a5, each number after the first is 5 times the preceding number. If a4 – a1 is 93, what is the value of a1?
For this question, it is best to choose simple numbers to see the pattern. If a1 is 1, then we know that a2 = 5, a3 = 25 and a4 = 125, so we know that a4 will be 5*5*5 or 125 times the value a1,. No matter what we choose as a1, a4 will always be 125 times greater than a1. We need to find a value such that 125x – x = 93

124x = 93
x = 3/4

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4 Steps for Two-Blank Sentence Equivalence Questions

One the Revised GRE, Sentence Equivalence questions contain one, two, or three blanks. Two of the answer choices (out of six presented on the GRE) will be correct, and you will need to understand both the meaning of the sentence/s as a whole and be able to identify the clues in the sentence to find the correct blanks. For better scores on GRE Verbal questions like these, follow these easy tips on your GRE Test Day!

STEP 1: Write down the keywords. As you read the sentence, you will be on the lookout for keywords, words that describe the blank or relate to the overall flow of the sentence (transition words). Write them down! It may seem redundant, but the act of writing them down will slow down your impulses and force your brain to think critically. What do the words tell you about the blank?

STEP 2: Write down a prediction for the easiest blank. Once you’ve analyzed the keywords and punctuation of a sentence, you can come up with a prediction for the blank which seems the most straightforward to you. It doesn’t have to be a great prediction, but make sure you do write something down. Even a simple prediction like, “a negative word” or “something like sad” is great! Don’t let yourself read the answer choices without a written-down prediction. If you don’t write it down, you will likely forget it as you read the answer choices.

STEP 3: Eliminate answer choices based on that prediction. Instead of scanning the answers quickly looking for the correct one, carefully move through the choices from A to F, eliminating the answer choices that could not possible match your prediction. Only worry about scanning the column for the blank you predicted for – don’t even read the other words.

STEP 4: Plug in for the remaining blank, if necessary. If you have more than two answer choices left after eliminating, then plug them into the sentence to see which ones are correct. Remember that for Sentence Equivalence, there will be two correct answers!

How to Handle Short Passages on the GRE

One benefit to the Revised GRE test is that there are two short Verbal sections with 20 questions each instead of one long section. Another is that you can now freely move back and forth between questions within a given section. This means that you will be able to answer look at questions and choose the order in which you can answer them.

According to the official GRE website, “reading comprehension passages are drawn from the physical sciences, the biological sciences, the social sciences, the arts and humanities, and everyday topics, and are based on material found in books and periodicals, both academic and nonacademic. The passages range in length from one paragraph to four or five paragraphs.”

So how should your approach change from longer to shorter passages? For longer passages, it makes sense to thoroughly read and take notes on the important information presented (main idea, function of each paragraph, author’s point of view, etc.). Shorter passages, however, will usually only be accompanied by 1-2 questions.

Therefore it makes sense to read the questions first before looking at the passage. Quickly identify the pieces of information you’ll need to find. For example, let’s say the first question asks about the “Main Idea” and the second question asks about the Logic behind the author’s use of a specific detail. You will only have two tasks as you read: find the purpose, and find out why the detail is included. There’s no point in trying to focus on the author’s point of view if it isn’t necessary to answer any of the given questions! Make your job as simple as possible.

Creating these clear tasks for yourself is an effective strategy for shorter passages, since you don’t have as much text to decipher.