Final Lap sprints - tips specially for the CAT takers

Dear Friends,
It's a very common experience with many of us and no one seems to be having a solution to it. The worst part of the story is that even though many would ask you to practice more you still dont find it working for you. Here i would like to ask you to take a break from your studies and just ruminate over your study methodology. I shall share with you my presonal experience and if you find yourself in a similar quagmire then i suppose the solution sighted by me may be of help to you.
I would like to bring it to your notice a fact that you must be aware of but would have never thought of it in this perspective. Any practice exercise that you take up has myrid problems of various diffuculty level. Apporachs for many of them are known to you. A Typical example of this problem would be :- Whats is the sum of all 3 digit numbers are there which are divisible by 7? This is a very typical problem on progression or numbers for that matter. Iam sure nobody would be able to give you the number off hand but alomst 90% can give you the approach atonce and the answer after a few min of calculations.
And there could be problems like :- mth term of an Ap is 1/n and nth term is 1/m then find the sum to mn terms? Now for most of us this problem is such where we dont have any approach. The traditional technique would be to write down some formulaes and then try to play some mathematical jugellery but in rare cases you would be successful, and your chances to succeed are further reduced if you take the exam pressure into consideration.
What you need to do in this case is to develop an approach to various such problems instead of spending your time on the problems with which you are comfortble. CAT is not an exam to test your speed. It used to be so earlier but the trend has changed off late. There is no sense practicing all those problem approach to which is already known to you unless you are thorugh with all the different varities. So my advice is you should first get a feel of all varities of problems and then go and practice each one individually.
A word of caution :- in doing to dont loose heart cause if you start attempting only the difficult problems you may end up frustrating yourselves in case you dont get the solutions to majority of the problems. But let me assure you, the more you practice on variety the better it is for your score in CAT.
Wish you Best of practice sessions.