Quant Suggestion Please...

You obviously know what to do in different question types - the point is - do you know WHY you do it. Higher level Quant questions require higher order thinking e.g. not just the application of a formula but whether you can produce one of your own when the situation demands.

For example:
I am sure you know how to find the sum of first n positive integers. You use the formula n(n+1)/2
But do you know why you use it?
1, 2, 3, 4, 5, ... n-1, n

Because we can find the middle number which is given by (n +1)/2 which is the mean of the numbers. We know that the mean represents that number which can replace every number of the set. So we can replace every number by (n+1)/2 and there will be n such numbers.
The sum = n(n+1)/2

Now, can you use the same logic to get the sum of first n odd numbers Or first n even numbers?
and so on...

This is just a small example. My mantra is that the more you ask 'WHY', the better your score gets. But don't expect overnight miracles. It will take some time but hard work invested wisely will certainly result in a higher score.