Friday, December 10, 2010

GRE Problem Solving

 When solving word problems, a reasonable real-world conditions. Do not get stuck looking for subtle meanings, it's not a bad section of the test-makers try to trick you that way.

If your question is mainly about interpretation of data analysis, graphs or tables, you should not rely on your eyes only for measuring the angle sizes, numbers are often not drawn to scale. Know what questions you should (or should) be visually estimated, and you should not.

Check out the most intuitive way to get the right answer. Problem solving questions are designed to be faster and shorter ways to get the same answer, so if you make a lot of work with pencil, stop and think a moment. There is probably a faster way.

The numerical value of response options increases in size as you read down the list. So if you estimate roughly the size of the number of questions asked so you can easily remove all but the most likely answer.

If you are stuck, many questions allows you to work backwards assuming hypothetically that each answer choice is right again, then test it "putting in."

Do not forget to check your work. Incorrect answers usually make mistakes predict ir fool you. Use a pencil and scrap paper so you can check the Processes tab, and calculate before choosing your final answer.

GRE Problems

The Arithmetic part of the GRE exam consists of several multiple choice questions on various topics, including:

    * Basic number properties

    * Fractions, decimals and percentages

    * Arithmetic word problems

    * Algebra- equations and inequalities

    * Averages, ratios, proportions

    * A tiny bit of probability, permutations/combinations, etc.

    * Geometry: lines, angles, triangles, squares, a tiny bit about circles, and coordinate geometry

Make sure you know all of these areas of math. They’re usually asked at an American high-school level, which isn’t very difficult to be honest.

There are approximately 10 distcrete-quantitative, or regular, math problems in the quantitative section of the GRE. You get about 1.5 minute per question, which means timing is crucial- you want to practice until you can solve these questions within the proper time limit.

Sample Problems:

On a coordinated grid with O(0,0), line AB goes from (0,3) to (3,0). Line CD goes from (0,4) to (4,0). What’s the area of ABCD?

Answer: In the GRE, you’ll likely be given a picture to help you, but here you should just draw it out yourself. The easiest way to solve this is to find the area of triangle AOB and subtract it from the area of triangle COD, as the remainder will constitute of area ABCD. Now, each perpendicular side of AOB is 3, so the area is . The area of COD is similarly . Therefore the remining area of ABCD is .

Question: , while . Find .

Answer: The trick here is to manipulate the equations you’re given to eliminate b. You can do this easily by adding two of the first equation to the second one: . Cool. Now, we know that , so . See, it’s pretty easy.