1. CALCULATING  FASTER

 2. VEDIC MATHS

CALCULATING FASTER

Maths in the Quantitative Ability (QA) and the Data Interpretation (DI) section is not only about solving the questions accurately but also solving them with speed

• For faster calculations  
• The Importance Of Reciprocal Percentages And Fractions
  
• Tips To Remember Some Values 
  
• Composite Table

1.For faster calculations

1. The first requirement is to mug up tables till 30, reciprocals with respect to percentage and decimals, squares & cubes till 30, square roots and cube roots till 7.

2. Practice various questions to become comfortable with the various types of problems and understand by which method you can solve a particular problem faster. Exposure to various types of questions is required so CAT does not come as a surprise to you.

3. Be very thorough with basics of all arithmetic topics like profit, loss and discount, ratios, basic number theory and formulas.

4. Take sectional tests and analyse your performance. This helps you to understand your strengths and weaknesses. Remember, a test is not conducted to tell you that you perform at 80% efficiency but to point out the 20% area where you are making mistakes.

5. Try vedic maths and learn short-cut methods that work for you. Also, try doing mental calculations and minimise the use of using pen and paper.

6. Approximation is the best tool to arrive at answers quickly but using it is an art, you will have to learn this through trial-and-error and practice.

7. Often you can arrive at the correct answer by the process of elimination. For some questions you may see that two or three of the given options are pretty far fetched and it is easy to select the right answer. Again, this method needs practice to perfect.

8. Whenever you try to calculate faster then your comfort zone speed, you are bound to make silly mistakes. So, try to build up your speed slowly so that it peaks in November when all the entrance tests are about to begin.


2.The Importance Of Reciprocal Percentages And Fractions

The CAT tests your ability to interpret and understand questions based on facts and figures. To tackle the QA & DI sections, you need to have a good understanding of number theory. Lets take an example.

Suppose you are to calculate 5.26% of 760 as a sub-step of a DI calculation say something like

 (526/200) X (760/100)  => {(5.26/100) X (760/1)} 1/20

You should know the equivalent fraction of 5.76% (It is actually 1/19 ), it reduces to (40) X 1/20 = 2

This can save you vital 15 – 20 seconds (at least) and saving this much time in almost every question means a higher attempt and higher accuracy.

So, be sure to spend time learning equivalent fraction & percentages from 1/1 to 1/30.

Here are some tables to help you out…
 

3. Tips To Remember Some Values 

The values of reciprocal percentages (RP) for 6 is exactly half that for 3 (half of 33.33 = 16.66)

The RP for 8 is exactly half of 4 (half of 25 = 12.5)

Seven is easy to remember just 7 into 2 (14), followed by 14 into 2 (28) which makes it 14.28

9 is one-third of 3 (33.33 divided by 3 = 11.11)

Please start with the next ten only after becoming absolutely comfortable with the first ten
 

By now you would have figured out that the difficult ones are the prime numbers. We have already dealt with 7. Now we need to work out 11, 13, 17, 19, 23 and 29.

9 and 11 are interrelated as 1/9 is 11.11 and 1/11 is 9.09
13 is considered unlucky. The way you remember it is through the year 1977,which proved unlucky for Indira Gandhi and Coca Cola.

All even numbers can be worked out by dividing the RP for the number that was their half or quarter by two or four respectively. For example, 12 is half of 6 (half of 16.66 = 8.33)

Workout the rest of the primes and your own unique way to remember them. We cannot emphasize the importance of having the percentages of the 1st 30 reciprocals on your fingertips.
 

4. Composite Table