The coaching institutes have created a myth that one should target at 90 percent accuracy and doing guesswork is disastrous but the truth is poles apart.
There are 3 core benefits to attempt all questions -
1. during mocks if you don't attempt all questions, you will never improve your speed and be forever constrained to solve only 20-22 odd questions and super easy papers are not uncommon since prometric and normalization days (i know of people who were super happy attempting 22 questions and later shocked to hear post exam that almost everyone they knew had same or more)
2. you will get to know your real strengths. As you know there is a difference between what you know and what you think you know, similarly there is a difference between what you don't know and what you think you don't know.
3. Probability - it is much more useful in life than just for exam sake, read along...
There are 3 types of people when it comes to verbal -
1. Those who could accurately assess at the time of giving mock that which question they could solve and which they could not
2. Those who are pretty sure of an answer at the time of attempting but often end up with wrong answer when they see the answer keys. Also, some questions they skipped as they were "not sure", are now found as correct
3. luckless fellas who mark 20-22 questions with a pre-set target of 90 percent accuracy but end with scores like 8-9 correct and rest wrong.
If you are type 1, congrats you are an "ideal" student, go collect your trophy.
If you are type 2 and 3, please stay away from toppers' and institute profs' advice. You are not a typical topper material.
The main fact to be considered is that each correct answer fetches you 3 while incorrect deducts 1. So, by the laws of probability even a "total dumb" person would end up with "0" after a round of guesswork. But, you being a graduate and highly intelligent person, will swing odds in your favour.
Plus, there is no reward for a 80-90 percentile, so don't play safe. In CAT, there are no rewards for mediocrity if you are general category student.
What? did you say you are not intelligent? then it makes more sense as you know, a 25 percent chance of success is better than 100 percent assurance of mediocrity
If you spend even 45 seconds assessing a question, you could as well spend another 30, choosing and marking an answer.
Coaching institutes have a vested interest in making you believe that accuracy is important because their whole business model is built around making you read and learn more, the more time you put, more loyal you will become to these institutes. I have seen several toppers swear by the fundas of these institutes and hence propagate the same to their juniors as well.
Remember, purpose of CAT is not to prove your intelligence, it is just a hurdle, cross it, by any method you can.
- scored 99.6 percentile twice without any coaching or "serious/sincere" preparation (gave CAT second time during 1st year to switch to a better b-school, my acads suck)