Welcome to “Land Your Score,” a blog series in which Kaplan instructor Jennifer Land shares key insights and strategies for improving your GMAT performance on Test Day. This week, Jennifer discusses how to solve Data Sufficiency problems using the Kaplan Method.
Today I’ll help you land your score by tackling another type of Quantitative Reasoning question. First, let’s get familiar with the Kaplan Method for Data Sufficiency.
The Kaplan Method for Data Sufficiency
Step 1. Analyze the question stem. The “stem” is the question part of the question, as opposed to the two statements. There are three components to this analysis:
- Determine whether it’s a Value or Yes/No question. The rules for sufficiency are a little different for the two types.
- Simplify. If the stem includes an equation that can be simplified, do so right away. A word problem should be translated into math or paraphrased.
- Identify what is needed to answer the question. By identifying what information would be sufficient, you’ll be better able to evaluate the statements.
Step 2. Evaluate the statements using 12TEN. I’ll explain Step 2 in my next post; we will concentrate on using Step 1 for now.
Value or Yes/No?
Let’s apply the Kaplan Method to this sample problem:
What is area of square ABCD?
(1) The longest line segment that can be drawn through any two points on the perimeter of square ABCD is 4√2.
(2) When a circle is inscribed in square ABCD, the longest line segment connecting two points on the circumference of the circle that can be drawn has a length of 4.
The answer choices never change:
Statement (1) BY ITSELF is sufficient to answer the question, but statement (2) by itself is not.
Statement (2) BY ITSELF is sufficient to answer the question, but statement (1) by itself is not.
Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, even though NEITHER statement BY ITSELF is sufficient.
EITHER statement BY ITSELF is sufficient to answer the question.
Statements (1) and (2) TAKEN TOGETHER are NOT sufficient to answer the question, requiring more data pertaining to the problem.
To analyze the question stem, we first determine whether we have a Value or Yes/No question. Here we need the area of a square: a value. There is no equation to simplify, so we next identify what we need to find the value; we are asked for the area of a square, so we need the length of a side.
Drawing line segments
One of the hardest parts of Data Sufficiency is remembering to consider each statement separately. Don’t let information from one statement carry over to the other. Each statement stands alone and must be considered by itself in conjunction with the question stem.
Statement (1) tells us the length of “the longest line segment that can be drawn through any two points on the perimeter of square ABCD.” To understand what this means, we need to draw the figure.
The longest line that can be drawn between two points on a square is the diagonal of the square. I’ve drawn it in red from point A to point C. If you’ve brushed up on your basic geometry, you know that the diagonal of a square creates two 45 : 45 : 90 degree triangles, and the side length ratio for a 45 : 45 : 90 degree triangle is x : x : x√2.
Is there sufficient data to answer the question?
Because we know the hypotenuse of this triangle is 4√2, we know x=4. That means the length of each side of the triangle (and thus, the square) is 4. This is all we need to find the area, so Statement (1) is sufficient.
Why do we not use the area formula and obtain the value that we were asked for? Because this is the GMAT, and we want to stop working as soon as we have the answer. The answer here is, “Yes, I can find the value I was asked for,” meaning the statement is sufficient.
We will attack Statement (2) and use Step 2 of the Kaplan Method next time!
Want to master Data Sufficiency on the GMAT? Visit Kaptest.com/gmat to explore our course options.
The post Land Your Score: Data Sufficiency Problems, Part 1 appeared first on Business School Insider.
