There are some reasoning tips which is help you for solving the reasongin fastly.

Study smarterly

When you study any topic.constrate on thats topic and marks the difficult words.try to distinguish between questions where you’re sure of the answer and those where you were simply guessing.

Strengthen the Argument

Find the logical gap and fix it with additional information. This is the ONLY type of GMAT question where additional information (outside of the question) can/should be used.

• Correct answers to this question type will:
• Connect evidence with conclusion better.
• Make conclusion stronger.
• Strengthen the evidence with new information (perhaps an assumption is needed to make the argument work

Strengthen/Weaken 

Strengthen/Weaken questions are the most common Critical Reasoning (CR) question type on the GMAT.

• Break down piece of evidence.
• Attack validity of an assumption.
• Don’t try to prove or disprove conclusion.
• Tip the scales.

Strengthen/Weaken 

Don’t be careless! Wrong answer choices often have exactly opposite of desired effect.

• Double-check that your answer satisfies the ques¬tion stem, not the opposite of the question stem.
• When you compare two items, you must be sure that the two items are indeed comparable.

Closely examine the stimulus.

Although passages in Reading Comp talk about concepts and use terminology you won’t need to comprehend fully, Logical Reasoning is different. You’ll have to measure every word in both the question stem and the stimulus. In my experience, test-takers often read too quickly and gloss over details, which causes the majority of errors here.

Eliminate all words that are irrelevant to the argument.

Even though you need to comprehend all the words in the stimulus, they’re not all important. The only words you’ll need to deal with are the ones that make up the evidence and conclusion.

Take a look at this:

Burritos are generally made with several ingredients including, but not limited to: ground beef, tomatoes, onions, and tortillas. No two burritos are made with exactly the same combination of ingredients. Thus, you can tell any two burritos apart by tasting them.

The opening line of this stimulus wasn’t evidence, and it wasn’t conclusion – it was simply the argument’s introduction, and didn’t play any meaningful role in terms of logic. You don’t need to worry about it once you realize this.