I am not a big RC cracker but with time i've improved my RC scores by following some basic methods.
I liked Kaplan's method for answering RC questions. And let me highlight how i use this method.
Firstly thing you've have to convince yourself is that you dont have to understand the RC passage thoroughly. DO NOT read the passage like you are going to present it in front of a crowd. The sole purpose is to get to the answers and there will be no question which asks you to explain the process described or the hypothesis stated in the passage.
Basically there are just 4 types of questions:
1. Whats the overall idea of the passage or the author.
2. What does the author mean when he says "........."
3. Which of the following is stated in the passage
4. What can you understand by ".........." mentioned in the passage.
Note that all the RC questions in GMAT wander around these same questions.
Method:
1. Taking notes is helpful, but do not waste time in taking notes on every sentence in the passage - this is useless.
2. When you land on a RC passage, write down the following on your booklet:
Topic:
Scope:
Purpose:
1:
2:
3:
3. As you read through the first line you may get an idea of what you are about to read. If not after the first para you would know it. Write down the topic on your booklet and write down what the first para said against 1:
4. Repeat the same after each para. DO NOT write a lenghty sentence against 1, 2, and 3. Just 3or 4 words indicating.
Eg: 1: Author proposes ......... theory
2: supports theory with reasons
3. Other theories - reasons for disagreement
5. Then write the scope and the purpose. The scope is the the statement summarizing the passage and purpose is the reason for writing the passage.
All this seems like a long time consuming process but no its not. Believe me. To accomplish this in 4 mins. read carefully and dont re-read details. Forget about the minor details such as the scientific process how blood flows from the heart to the arteries etc etc. Even if you dont understand it you'll be able to write against the passage that "Process of blood flow" This is enough.
Now when you look through the questions, i'm sure you'll be able to nail each answer because you have a perfect roadmap for the passage.
With some practice, i take 4 to 5 mins on the passage and less than 1 min on each questions. A moderately lengthy passage with 4 questions takes me 8 mins to solve with atleast 3 of them correct!!!!!!
Hope this helped.