The GMAT Data Insights section contains five types of questions. This post will focus on Data Sufficiency. On the GMAT, the format of each Data Sufficiency problem is the same: you’re given a question and two statements. It’s up to you to decide whether the statements give you enough information to answer the question. You don’t need to give the answer to the actual question. You just have to decide whether either statement (or both statements) gives data that is sufficient for finding an answer—hence the term data sufficiency! What is GMAT Data Sufficiency? The Data Sufficiency (DS) question ..read more

What’s the biggest secret to GMAT math success? It’s simple! Identify and study the correct quantitative concepts, strategize for problem solving, and leave rote memorization at home. The GMAT Quantitative section gives you 45 minutes to answer 21 questions. It’s an adaptive test, meaning that correct answers lead to questions of increasing difficulty. Incorrect answers have the opposite effect. Don’t let that worry you! This is just how the test finds your math ability level. Here’s a bit of relief! You’ll never encounter questions that require more than a basic high school understanding of ..read more

The GMAT Data Insights section excels at creating problems that frustrate folks who try to get through math by memorizing formulas.   It excels at creating out-of-the-box problems that really demand folks use logic and number sense to dissect the problem.   Here are four out-of-the-box Data Sufficiency problems to consider. 1) Peter went to the store to buy paint.  Small cans cost $30 and larger cans cost $80.  How many small cans of paint did he buy? Statement #1: Peter spent $220 on paint. Statement #2: Peter bought four cans of paint in total. 2) In a card game ..read more

Among other things, this post is a case study of an OG DS question: OG 12th Edition, Data Sufficiency Practice Problem #23 Here is the problem that appears in the OG: 23) If p1 and p2 are the populations and r1 and r2 the number of representatives of District 1 and District 2 respectively, the ratio of the population to the number of representatives is greater for which of the following districts? (1) p1>p2 (2) r2>r1 (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 i ..read more

How do we know what the possible values for a variable on the GMAT are?  First of all, consider this DS problem 1) Is P > Q? Statement #1: P = 5*Q Statement #2: P = Q + R For folks who are not as comfortable with math, or are a bit rusty with math, may fall into any one of a number of traps here.  Nothing is specified about any of these three variables, and on the GMAT, when nothing is specified, we have to assume that every category of number is possible.  This means we have to consider a) 1 (the great exception to many rules) b) 0 (another great exception to many rules c) p ..read more

Fact: One type of chart about which the GMAT DI can ask is a bubble chart. What in Sam Hill is a bubble chart?   Scatterplots A bubble chart is a close cousin to a scatterplot.  In a scatterplot, each data point has values in two different variables, and for each data point, its vertical & horizontal position on the graph tells its value in those two variables.  For example, here’s a scatterplot:   Each dot on this scatterplot is a company.  The vertical position of the dot tells you the 2011 revenue of the company.  The horizontal position tells you the year ..read more

One reason we graph data in a scatterplot is because we are looking for patterns.  The simplest of all possible patterns to find on a scatterplot is a straight line pattern. Correlation When the points on a scatterplot lie more or less in a straight-ish line, that is called correlation.  When it’s a straight line with a positive slope, going up to the right, that’s positive correlation, and when it’s a negative, slope, that’s negative correlation.  To say that A and B have a positive correlation is to say that when A goes up, B goes up.  Here’s an example of a graph with a ..read more

On the GMAT Quantitative section, there is no calculator.  On the Data Insights section, there is a built-in calculator.  The calculator that comes with GMAT’s official DI practice questions is quite similar, almost identical, to what you will see in the test.  Here is a brief tour of that calculator. The Calculator First of all, there are ten digit buttons, four buttons for the four fundamental arithmetic operators (add, subtract, multiply, divide), a plus-or-minus button, decimal, and an equal sign.  I am assuming that these are self-explanatory, as they appear in virtu ..read more

The following is a set of four GMAT Data Insights MSR questions. There are two information cards in this question. You are allowed to use a calculator. For the set of four, give yourself 10 minutes.   The cards The questions 1. Player A initially draws three-of-a-kind and chooses not to discard at all on the discard round.  Player B initially draws three-of-a-kind, discards the remaining two cards.  For the following final card combinations of Player B, tell whether Player A outscores Player B. 2. Suppose player J draws two pair and chooses not to discard any cards.  Sup ..read more

Unlike Problem Solving, Data Sufficiency is a question-type unique to the GMAT.  Data Sufficiency is part of the Data Insights section on the GMAT. GMAT Data Sufficiency Practice Questions 1. Maggie is 15 years older than Bobby.  How old is Bobby? Statement #1: In 3 years, Maggie’s age will be 50% larger than Bobby’s age. Statement #2: Years ago, when Maggie was 25 years old, Bobby was 10 years old. 2. By abc we denote a three digit number with digits a, b, and c.  Is abc divisible by 3? Statement #1: The product of (a) times (b) is a number divisible by 3 Statement #2: c = 3 3 ..read more