GRE- Complete information-Test tips
The GRE is now only available as a computer-adaptive test. This is how it works: instead of having a pre-determined mixture of easy, medium, and hard questions, the computer will select questions for you based on how well you are doing. The first question will be of medium difficulty; if you get it right, the second question will be selected from a large group of questions that are a little harder; if you get the first question wrong, the second will be a little easier. The result is that the test automatically adjusts to your skill level. The Tough questions have more credit than easier ones.
You can still earn a very high score even if you answer several questions incorrectly. Correct answers to Harder questions leads to large score as compared to easier questions. This means to Get large score more difficult questions has to be answered.

Some (Very few) Universities may demand Subject GRE.
After completing your exam you can send your scores (free!) to four Universities so be prepared.
Your GRE scores are valid for 5 years.
You may appear again in GRE after one month.

Section Questions Duration
Verbal 30 30
Analytical 2 writing Tasks 75
Quantitative 28 45
Verbal/Quant./Anal. 30/35/2(writing tasks) 30/60/75

Types of Questions

Analogies 7*
Sentence Completion 6*
Antonyms 9*
Reading Comprehension 3*

Mathematical comparisons 14*
Problem Solving 10*
Chart 4*

2 writing Tasks
*a 45-minute "Present Your Perspective on an Issue" task and a 30-minute "Analyze an Argument" task. The "Issue" task states an opinion on an issue of general interest and asks you to address the issue from any perspectives you wish, as long as you provide relevant reasons and examples to explain and support your views.
*The "Argument" task presents a different challenge ? it requires you to critique an argument by discussing how well reasoned you find it.
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Some Facts

Maximum score for sections Verbal, Quantitative is 800. An analytical writing score will be reported on a 0-6 score scale, in half-point increments.
GRE is generally required by universities in North America (USA and Canada).
Most Universities require General GRE for admission to MS and Ph.D. in Engineering Sciences.
Generally for engineering Students score above 1800 (750+ 450+ 4) is considered good for admission for middle order universities ranked between 40 to 90 .There may be some deviations.
For all engineering Students GRE Q is most important for best results GRE Q must be well above 740 ,GRE A above 650(A>4.0/6.0), GRE V above 450.
GRE score can considerably improve University Ranking. TOEFL is most important. TOEFL score must be well above 213.Generally
Top 50 ranked Universities may require GRE>2000(770+,500+,>4/6) and TOEFL>250.For International students Verbal section is quite difficult. So they must prepare hard on vocabulary.

Note: Work hard in GRE Quantitative. Work on Permutation/combination, probability, mean/median/mode... etc.