I see LGM's and GM's solve problems at a high speed. Even before me trying to understand the question.
I want to know how do you get that speed.I know people simply say by practice.
Can you be somewhat precise like what is frequency of problems you solve a day? ,how much time do you spend on solving a particular problem if you are struck? what is correct time to watch editorial?
I just want to know these things.I am trying but I am taking long time to solve them.Sometimes I spend more than 3hrs on some questions just for getting the idea even then I wouldn't be able to solve them.
Not an LGM or a GM, but, at the risk of restating the obvious, you just need to practice. Comprehension skills are developed through enough practice. To solve problems fast enough, most people rely on past experience and skills they've picked up from practice.
There is no "one true way" to get to that stage. Stick to a frequency that works for you, think deeply about problems and try to take away as much as possible from the problem (for instance, can you generalize the idea used in the problem? While solving the problem, what triggered the solution?). Experiment and change your approach if it doesn't work.
But yes, spending 3 hours on a (supposedly easy) problem is perhaps a bit too much. What works for a lot of people is to practice problems about 200-400 rating points above their rating (too easy problems give you no returns, and too hard problems are a waste of time), try to solve it for 30 mins to 1 hour and look at the editorial for hints (or even better, ask someone they know IRL for help), and if it is something completely new, learn about it.