## Tackle Options in GMAT DS Questions the Oak’s Academy Way

~ by our Quantitative Reasoning Faculty

Step 2 of the Approach to DS Questions: Tackle the Options the Oak’s Way

Step 1 of the approach dealt with carefully reading the question statement (see previous blog). Once that is done you have to deal with the options, which are standard in DS questions:

(A) Statement (1) alone is sufficient but statement (2) alone is not sufficient to answer the question asked

(B) Statement (2) alone is sufficient but statement (1) alone is not sufficient to answer the question asked

(C) Both statements (1) and (2) together are sufficient to answer the question asked, but neither statement alone is sufficient

(E) Statements (1) and (2) together are not sufficient to answer the question asked and additional data are needed.

To deal with them in the most systematic way possible just follow the sufficiency/insufficiency table below. It offers the best way of thinking through the options

## A Few Great Tips on How to Tackle the GMAT DS Questions

by our Quantitative Reasoning Faculty

In last time’s blog we looked at why DS is so important in GMAT. In this one we’ll take a look at the 3 key things that you need to do in order to tackle this unfamiliar question type. There are:

1. Learn the Options

The first step in learning DS is to get absolutely familiar with the options. Fortunately, in DS, this is easy because the five options are always as follows:

(A) Statement (1) alone is sufficient but statement (2) alone is not sufficient to answer the question asked

(B) Statement (2) alone is sufficient but statement (1) alone is not sufficient to answer the question asked

(C) Both statements (1) and (2) together are sufficient to answer the question asked, but neither statement alone is sufficient

(E) Statements (1) and (2) together are not sufficient to answer the question asked and additional data are needed.

2. Remember the Aim

Remember, in DS our aim is NOT TO FIND THE FINAL ANSWER to the question but  just to verify whether the INFORMATION GIVEN IN THE TWO STATEMENTS IS SUFFICIENT TO REACH TO THE FINAL ANSWER!

So while solving the question if, at any intermediate step, you realize that you can reach the final answer then QUIT and mark the option accordingly.

3. Understand the Approach

Now let’s have a look at how you should approach DS questions.

Step 1: Carefully Read the Question Statement and Find the Crux of the Question

After closely examining the question statement and before you read the information given in statements (1) and (2), ‘identify the crux of the question’. What I mean by ‘the crux of the question’ is the piece of information that is the key to the solution. Sometimes you have to think a little bit before you get it. But once you have it, it will lead you straight to the answer. For example, have a look at this question statement:

If x and y are distinct positive integers then:

(1) x = 2 (y + 3)

(2) x2 = y2 + 4

Now, if you have lost touch with maths, just the sight of that forest of terms is enough to want to make you give up. But again, remember that we are not at all interested in solving this inequality. We just need find out whether the expression on the left hand side is positive or not (that’s what is implied by >0) – and this is a much simpler matter! Further, in this mass of algebraic symbols is a key that reveals itself when you examine about the expression and think about it a little.

In order to get this key, the first thing to do is to carefully observe the question statement. First and foremost, it says, that x and y are distinct positive integers. This is a very important piece of information – and you’ll understand why in a moment. Secondly, if you observe the numerator of the expression on the left, it consists of additions throughout. Given both these pieces of information, the numerator has to be positive in nature: it is the sum of distinct positive integers (which is why the information about x and y was important). By the same logic, even the second bracket in the denominator has to be positive. The only unknown factor, therefore, is the first bracket in the denominator, i.e., (x – y) and this is what holds the key to the entire problem.

The entire expression will be positive if and only if (x – y) > 0, in short, if x > y. On the other hand, if x < y, the whole expression will be negative. So, the whole gigantic problem is reduced to an extremely simple question: is x > y? Once we have arrived at this conclusion, cracking the rest of the problem is really easy: any information about the relative magnitudes of x and y will be sufficient to arrive at the answer! Thus, in this case, the crux of the question (the key to the solution) is realizing that all we need to find out in order to answer this question is whether statements (1) and (2) allow us to decide whether x is bigger than y or vice versa.

Once you have reached this stage you are can confidently take on the options of this seemingly insoluble problem. The discussion above takes care of Step 1 of the approach i.e. carefully reading the question statement and finding the crux of the question. In the next post we’ll look at Step 2 of the approach: tackling the options in DS questions – and we’ll be giving you tips that will reduce the complexities to a few simple steps! Watch for the tips in our third DS blog post next week.

## GMAT Prep – Preliminary Reading and RC Practice

One of the most important aspects of preparing for reading comprehension in the GMAT is preliminary reading – that is, reading to be done before you start tackling GMAT RC passages in order to prepare you for the challenges that those passages will throw up.

One challenge that you will face on Reading Comprehension passages is that they tend to be about unfamiliar topics and concepts; and talk about unfamiliar terms and fields. They use difficult phrasing and vocabulary, and complicated sentence structure. The only way to get used to the level of complexity you will find in GMAT passages is to read widely.

Another challenge is the fact that reading passages on screen means that you may not be able to see the whole passage at a time, and may have to scroll up and down to read the rest of the passage. This is very different from reading on paper, where you can usually see the whole passage on screen at a glance. The fact that you can’t see the whole of the passage at once when you read long passages onscreen, makes comprehending the passage much more difficult.

## Write Better Essays with OWL – A Simple Aid to Improving Grammar

For GRE and GMAT test-takers, the Analytical Writing Section may sometimes seem to be an uphill climb. With only a half an hour to brainstorm ideas, make an outline and finally type in the entire essay, it may not always be possible to transfer your thoughts to the word processor exactly as you want. The result is often essays that fall short of what the examiner expects in order to award a 4.

The links below are a part of the Online Writing Lab, a project started by Purdue University, which helps teachers and students in developing their English Language skills and rectifying the errors that they make in their essays. They provide valuable suggestions on how to structure sentences correctly and avoid minor errors in English that we as non-native speakers of the language tend to make. Visit them and start improving your Analytical Writing essays immediately.

Note: if you are taking the TOEFL exam, these links will be a big help to you too.