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


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


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


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 &


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


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


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


Remainders (Quantitative Aptitude) for CAT Exam Preparation – Free PDF for Download

May 21st, 2018 by

Remainders, as a topic, confuses a lot of students. As a matter of fact, a large percentage of CAT quantitative Aptitude questions and doubts on any public forum (Pagalguy / Quora / Facebook) will be dealing with remainders. This is true for the Course Feed of my online CAT coaching course as well. So, I decided to combine all the various kinds of Remainder related questions and make a single post about it. I hope that if you go through the 50+ questions given in this post, you will never struggle with remainders again. In case you have any doubts with any of the questions, use the commen


Permutation and Combination – Fundamental Principle of Counting

July 15th, 2017 by

For this series of articles, I am assuming CAT 2019 would be the first time you would be attempting CAT, which essentially implies that you are not well versed with the basic ideas behind the Quantitative Aptitude portion. In the latter half of the year, I would move to slightly more advanced topics as by then, you would also have moved to the advanced stage of preparation. Best Online Coaching for CAT 2019 I have often seen students struggle with the topic – ‘Permutation & Combination’. As a matter of fact, I have even seen some faculties shy away from conducting those cl


Algebra for CAT Preparation – Finding smallest value in a maximum function

March 24th, 2015 by

A common type of question that gets asked in CAT is when you are given a maximum function and you are supposed to find out the minimum value of the function. Actually, the concept would remain the same even if you are given a minimum function and you are supposed to find out the maximum value of the function. To solve such kind of questions, all you need to do is to find out the point of intersection of the individual values. More often than not, that would lead to the answer. Let us look at a question that has appeared in CAT before. Let g(x) = max (5 − x, x + 2). The smallest possi