Number System Syllabus for CAT Exam Preparation

March 10th, 2015 by

Number System There is common perception that Number System questions form the most important part of the CAT syllabus and something that cannot be neglected when it comes to CAT Preparation. While I agree with the latter half, I strongly object to the first part. The perception about Number System is such because when you consider all chapters of CAT Syllabus, It is probably the most important but when you compare it with other categories - it loses its relevance. You have to understand what you are comparing it with. If you are comparing with another chapters like Time, Speed, and Dista

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Basic Functions and Modifications of Graphs

February 16th, 2013 by

Basics of functions and modifications of graphs   XAT’s Quant is always a little bit on the tougher side. It is said that the paper would be do-able and the level of difficulty will see a dip. That does not mean that the difficulty level would suddenly drop to the standard of elementary mathematics. XAT traditionally focuses more on topics like functions, probability, permutation & combination, etc. more than the CAT exam. In this post we will discuss some basic tips about functions and how graphs of functions change. Let us see what the function y = f(x) = x3 + 7 looks like:

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Remainders Advanced

February 15th, 2013 by

REMAINDERS ADVANCED   In previous posts, we have already discussed how to find out the last two digits and basic ideas of remainders. However, there are theorems by Euler, Fermat & Wilson that make calculation of remainders easier. Let’s have a look at them.   Funda 1 – Euler:   A very common mistake that students tend to make while using Euler’s Theorem in solving questions is that they forget M and N have to be co-prime to each other. There is another set of students (like me in college) who don’t even understand what to do with the theorem or

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Basic Application of Remainder Theorem

February 15th, 2013 by

Basic Applications of Remainder Theorem     In my previous post, we discussed the cyclical nature of the remainders when an is divided by d. In this post, we will see how problems on finding out the remainder can be broken down into smaller parts.   Funda 1: Remainder of a sum when it is being divided is going to be the same as the sum of the individual remainders.   Let us look at an example for this case: Eg: Find out the remainder when (79+80+81) is divided by 7. If we add it up first, we get the sum as 240 and the remainder as 2 as shown bel

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Cyclicity of Remainders

February 15th, 2013 by

Cyclicity of Remainders   In this post I would like to discuss some of the really fundamental ideas that can be used to solve questions based on remainders. If you have just started your preparation for CAT Exam, you might find this article helpful. On the other hand, if you are looking for some advance stuff, I suggest that you check out some of my posts from last year on the same topic. First of all,     What I am trying to say above is that if you divide a^n by d, the remainder can be any value from 0 to d-1. Not only that, if you keep on increasing the

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A puzzle on Facebook (Source: XAT-2013)

January 25th, 2013 by

Sara has just joined Facebook. She has 5 friends. Each of her five friends has twenty five friends. It is found that at least two of Sara’s friends are connected with each other. On her birthday, Sara decides to invite her friends and the friends of her friends. How many people did she invite for her birthday party? (A)  ≥ 105  (B) ≤ 123        (C) ≥ 125        (D) ≥ 100 and ≤ 125 (E) ≥ 105 and ≤ 123 Solution:  The key point: “Each of Sara’s 5 friends has twenty five friends” => Sara is one among these 25 friends.

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