GMAT Quantitative questions are normally considered to be easier than their GMAT verbal cousins. Most applicants from an engineering background score high on the GMAT quant section. But just because they are the low-hanging fruits, doesn’t mean you can take them lightly as a higher GMAT score would require you to crack difficult GMAT quantitative questions. In this post for MBA Crystal Ball, the experts from GoGMAT provide an overview of the Problem Solving and Data Sufficiency type of questions in the GMAT maths section.
The Quantitative section, or Math section (as it is usually called), measures your skills at problem-solving, basic math, and understanding of elementary mathematical concepts. This section comes second on the test, between Analytical Writing and the Verbal section. There are two optional breaks one before and one after Math section.
Your score for the Math section depends on both your performance and the difficulty of the questions. The score is presented on a scale of 0–60, but the highest score you can get is 51. This score along with the Verbal score is transformed into the GMAT Total score that ranges from 200 to 800. It is crucial to perform well on the Math section in order to receive a high Total score.
The Quantitative section takes 75 minutes and consists of 37 multiple-choice questions; that means you should spend on average two minutes for each problem.
There are two types of questions: Problem Solving and Data sufficiency. They are mixed together within the section, and each of them offers five different answer choices.
Problem Solving questions are typical test problems. Here is an example:
All you need to do is choose the right answer. For this problem, the right answer is A. You must multiply both numerator and denominator by (√11 + √10) and expand the product (√11 + √10)(√11 – √10) that equals 1 :
Keep in mind that there is a single right answer for every problem. Answer Choice C and Choice E both represent 1; therefore, they can be eliminated right away.
Sometimes Problem Solving questions include statements identified by Roman numerals, and you are asked to choose which of them is/are correct. Let’s take a closer look at the next problem:
If x increases from 121 to 144, which of the following must increase?
I. 11x- 12
II. 1 – 11/x
III. 1/( – 169x)
(A) II only
(B) III only
(C) I and II
(D) I and III
(E) II and III
Begin with the first statement. The expression (11x – 12) increases as x increases. Thus, statement I must be included in the right answer, and we can immediately eliminate Choices A, B, and E. Now you must choose between Choice C and Choice D. You can test either second or third statement, but it is better to start with the simpler one, so test statement II. When x begins to increase, 11/x is decreasing. However, 1-11/x is increasing because the decreasing amount 11/x is subtracted. Finally, therefore, the right answer is Choice C. You do not need to investigate statement III at all in order to answer the question, since you have demonstrated that Choice C is correct.
Data Sufficiency (DS) is a question type peculiar to the GMAT. Each question is followed by two numbered statements that purport to provide information useful for answering the question.
As usual, five fixed answer choices follow each question.
Here is an illustration of a Data Sufficiency problem:
If y+40x+2=0, what is the value of xy?
(2) 13y =91–52x
(A) Statement (1) ALONE is sufficient to answer the question but statement (2) alone is not sufficient.
(B) Statement (2) ALONE is sufficient to answer the question but statement (1) alone is not sufficient.
(C) The two statements TAKEN TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient.
(D) EACH statement ALONE is sufficient to answer the question.
(E) The two statements TAKEN TOGETHER are still NOT sufficient to answer the question.
We have one linear equation with two variables provided in the question. We cannot solve it unless we have another independent linear equation. Each of the statements alone is sufficient, because each provides a second, independent linear equation and thus allows to calculate a single pair of x and y and the value of xy. Hence, the right answer is Choice D.
Note that you do not have to calculate the value of xy. As soon as you know that you have sufficient information to calculate it, or that the information is insufficient, you can pick the right answer choice.
The Math section will consist of no more than 2/3 Problem solving questions and at least 1/3 Data Sufficiency questions distributed in a random order within the section. Some problems will include graphs, charts, and figures. All numbers used in the test are real numbers.
You are not allowed to use a calculator for the Quantitative/Math section, but you will have a whiteboard and erasable marker to make calculations.
The material covered in the Quantitative section includes arithmetic, elementary algebra, and geometry. You do not need to know advanced math; a solid high school background is sufficient. You will be expected to demonstrate your proficiency at manipulating numerical operations, solving algebraic equalities and inequalities, building mathematical models of verbal problems, and visualizing geometric objects and logical relationships. To achieve the highest scores, you must quickly apply non-standard solution methods.