Examinations are there to make all the rest know whether you know the answer or not. By having the right or wrong answers it can be determined whether you pass or not. The more right answers, the better the chance of passing. It is the way of the academic life. It is also the basis of most employers who hire. Whether you are good in guessing or not, it does not matter as long as you get a very good score. If you know that you are academically challenged do something like go for an online gre practice so you know how it feels. Passing is not a guarantee you can land on the job but at least it can get you to the next level.