Factorial Concepts for CAT – Rightmost digit, Ending Zeroes, Power of a Prime

March 15th, 2019 by

We all know what factorials (n!) are. They look friendly and helpful but looks can be deceiving, as many quant problems have taught us. Probably it is because that Factorials are simple looking creatures, most students prefer attempting questions based on them rather than on Permutation & Combination or Probability. I will cover P&C and Probability at a later date but in today’s post I would like to discuss some fundas related to factorials, which as a matter of fact form the basis of a large number of P&C and Probability problems.   Some of the factorials that mig

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Time Speed Distance – Motion of Two Bodies in a Straight Line

March 13th, 2019 by

There are some topics in Quantitative Aptitude, like Permutation & Combination,  where you can easily find out the answer and the answer you calculate is there in the options but it turns out to be wrong. And then there are some topics in which you read the question, understand it but cannot even begin solving it. You get stuck at the first step and you have no idea about how to even approach the question. The irritating fact is that you understood the question properly. It happens very frequently with questions on Time Speed & Distance (TSD). I have always been a big advocate of

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Determining the second last digit and the last two digits

March 1st, 2019 by

Nike caused controversy with its advertising campaign during the 1996 Olympics by using the slogan, "You Don't Win Silver — You Lose Gold." Nike's use of this slogan drew harsh criticism from many former Olympic Silver medallists. In a way, it did undermine the importance of the second position but in Math things are often very different. Figuring out the second last digit is often tougher than figuring out the last digit. It is unlikely but definitely not impossible that in CAT you get a straightforward question that asks you to find out the second last digit of a number (abcpqr). In fe

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Number System Concepts for CAT – Even Factors, Odd Factors, Sum of Factors

February 22nd, 2019 by

let me first list down the topics that I am going to cover in this particular blogpost: Number of factors of a given number Number of even factors or odd factors of a given number Sum of all factors of a given number Sum of all even factors or odd factors of a given number   We know that a number N can be written as a product of its factors as given below   N = ap x bq x cr … Here a,b,c… are prime factors of N & p,q,r … are the powers of the prime factors of N.   In such a case the number of factors of N are given by the formula &

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Divisibility Rules for CAT Quantitative Aptitude Preparation

February 20th, 2019 by

The concept of ‘divide and conquer’, derived from the Latin phrase ‘Divide et impera’, was put into use effectively by everyone from Caesar to Napoleon to The British in India. Even Gaddafi tried using the same but as current events show us – he wasn’t very effective. Dividing rather divisibility rules to be specific can come in really handy at times in solving problems based on Number Systems. The standard rules which nearly all of us are very comfortable with are the ones for 2n and 5n. For these all that one needs to do is look at the last ‘n’ digits of the number. If

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Averages Concepts from Arithmetic – How to apply in CAT Questions?

February 16th, 2019 by

Average is mainly defined as the sum of observations divided by the number of observations. Keeping in view the Quantitative Aptitude section of any competitive exam and especially CAT, 1-2 questions are asked from this chapter. It is not a difficulty chapter if you know the tricks to solve the question in very less time. Averages Concepts and Properties: Average= (Sum of observations)/(Number of observations) Important Points: In past year Cat questions, a number of times concepts of age/height/weight and average has been mixed together. Here are some important points to remember

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CAT Quant – Escalator Based Problems in Time, Speed, and Distance

January 29th, 2019 by

Escalators has now become a topic from which questions are asked quite frequently in CAT. Today, we are going to see the theory behind escalator questions and solve them through both equations and ratios. Once you are through with the concept and are able to solve the questions in this article, you can solve any question from this topic Escalator questions are very similar to the upstream and downstream questions. In a stream, the direction of flow of water is constant whereas, the escalators move in both directions. Escalator questions can be confusing as sometimes, questions might not

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Permutation and Combination – Distribution of Objects

October 16th, 2018 by

As an astute man Mr. Gump once said, “Life is like a box of chocolates. You never know what you going to get.” The Permutations and Combinations that life presents us daily is baffling and probably it is because of that inherent fear of choices and cases we get intimidated by such questions in the exam. I understand that Permutation and Combination is one of the dreaded topics but I hope that once you understand the fundas given below, your fear will reduce. Permutation and Combination Funda 1: De-arrangement If ‘n’ distinct items are arranged in a row, then the number of way

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Geometry Fundas for CAT Quantitative Aptitude Preparation – Part 2

June 19th, 2018 by

In the previous post we discussed lines, triangles, parallelograms, trapeziums, polygons etc. Now, we will discuss other expanses of geometry which are vital as, the questions on these topics are asked repeatedly in CAT. Let us look at few of the fundas / formulae on these topics that are often neglected by students and can fetch some crucial marks in the exam. Funda 1: Angle made by Secants       2 .   In both these cases, PA * PB = PC * PD   Funda 2: Common Tangents     eg: Note: The two centers

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Geometry Fundas for CAT Quantitative Aptitude Preparation – Part 1

June 18th, 2018 by

I got a lot of feedback via emails and texts that people are looking for a post on geometry. I have been avoiding it for sometime because of two main reasons: a)      It is not one of my strong areas. b)      It takes a lot of time to draw the diagrams that are sometimes required to explain the fundas. The questions on geometry are the trickiest and consumes the maximum amount of time as compared to the questions on other topics in Quantitative aptitude that is why, I have compiled a list of fundas that you might find helpful in solving CAT level questions. I am splittin

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