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The perception with a lot of students with regards to CAT is that CAT is for Engineers. A non engineer finds it difficult as there is a lot of Math in CAT. Most of the students tend to give up on CAT as they can’t find how to break the Math conundrum. They learn formulae by rote and try to use the formulae in different sums in the Mocks only to realize that their scores are not improving.

The whole concept of learning formulae by rote for CAT is flawed. CAT does not check how good you are at remembering formulae and for most of the sums in CAT you cannot apply formulae directly. Rather, CAT checks whether you can logically think through sums. Its not about how much You study from Preparatory material but how smartly you can imply what you have learnt.

If you look at the previous CAT papers, most of the sums can be solved without the use of any high funda formulae. The whole thing about learning Euler’s Formula, Chinese Theorem, etc is basically useless. Rote learning formulae just makes you focus on formulae and you try to wonder which formulae to use for the sums. Frankly speaking I do not know any of these high funda formulae. I don’t know what is Euler’s formula or Chinese Theorem or most of the formulae which are used by various classes to solve their sums in the Mock CATs. As a matter of fact, some of the formulae which I encounter in the Mocks of these papers are new to me and I do not bother to read it, but still in the given time I could get 78 marks in Math section in CAT '07 and 90 marks in Math section in CAT '08 both the years scoring 100%ile. Understand this - that CAT does not check on your mathematical skill but on your reasoning skills. Let’s try and understand how using formulae or equations can make you slow.

Example: Lets take a question from CAT '08

A shop stores x kg of rice. The first customer buys half this amount plus half a kg of rice. The second customer buys half the remaining amount plus half a kg of rice. Then the third customer also buys half the remaining amount plus half a kg of rice. Thereafter, no rice is left in the shop. Which of the following best describes the value of x?

(1) 2 ≤ x ≤ 6 (b) 5 ≤ x ≤ 8 (c) 9 ≤ x ≤ 12 (d) 11 ≤ x ≤ 14 (e) 13 ≤ x ≤18

Solution:

Usually students who are used to formulae and equation will tend to use x as the initial amount of rice and try to form an equation to solve the sum. A better way would be to go reverse way. Say the last person has no rice left after he was given half the rice plus half a kg of rice. So he would have (0+1/2) x 2 = 1 Kg before the last customer came in. Similarly before the second customer had come the shopkeeper would have (1 + ½) x 2 = 3. Before the first customer came in the shopkeeper would have (3 + ½) x 2 = 7 kgs which is the answer.

Another question from CAT '08:

Find the sum √(1+ 1/1² + 1/2²) + √(1 + 1/2² + 1/3²) + ….. + √(1 + 1/2007² + 1/2008²)
(a) 2008 – 1/2008 (b) 2007 – 1/2007 (c) 2007 – 1/2008 (d) 2008 – 1/2007 (e) 2008 – 1/2009

Solution:

It is almost unsolvable by using equations. But use the first term √(1+ 1/1² + 1/2²) and we get 3/2 = 2 – ½. The denominator of last number of first term is 2. Take two terms√(1+ 1/1² + 1/2²) + √(1 + 1/2² + 1/3²) = 3/2 + 7/6 = 8/3 = 3 – 1/3. The denominator of the last number of second term is 3. So the answer has to be 2008 – 1/2008.

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The article has been written by Patrick D'souza, BE, MMS from JBIMS and a CFA for TestFunda.com. Testfunda.com, is the Leader in Online MBA test preparation & is managed by a team of 4 IIT-IIM Alumni backed by a team of  85+ Educationists, Instructional Designers and Systems Architects with vast experience in MBA Coaching and Computer-Based Training-Testing.