# Aptitude

## [Aptitude] Permutation Combination made easy without Formulas

If the following questions make you uncomfortable, then read this article. In how many ways can 5 member committee be formed out of 20 students? Or How many ways can the word “UPSC” be arranged so that “U” is always second from left. In [...]

## [Aptitude] PnC: arrange such that two people Always sitting together?

Q. How many ways can four children be made to stand in a line such that two of them A and B are always together? (-asked in UPSC Prelims 2010) Confused? You won’t be, after reading this. DONOT Proceed further, without reading The First article on [...]

## [Aptitude] Trains, Platforms TSD (Time,Speed,Distance) made easy

Main-Topic: Time, Speed Distance (TSD) Subtopic: Trains and Platforms. you’ll be given some data and asked to find the length of railway platform or speed of train etc. Visualizing the Concept: Train and Pen Case 1: One Train One Man (or Tree, Pole) Case 2: One [...]

## [Aptitude] Probability Made Easy (Extension of Permutation Combination Concept!)

Introduction Case1 : Probability of Particular Actor getting selected Case 2: Probability of One lady getting selected Case 3: One man and one woman (“AND” case) Case 4: “Atleast” one man is selected (“OR” case) Alternative method: 1 Minus Case 5: Probability of [...]

## [Aptitude] PnC: How many Ways to arrange letters of word “RECUPERATE” (Permutation without Formulas)

When you form words using alphabets (or letters), the ‘order’ matters. Three alphabets T,A,C Now you form words: CAT is not same as ACT; both words have different meanings hence order matters. This is a permuation problem. Case 1: All letters are different Case 2: Word [...]

## [Strategy] The Art of Preparing for Aptitude Exams

Rule #1: Maintain a Diary of Mistakes Rule #2: Get your hands “DIRTY” Rule #3: Know when to give up the fight. The Mock-test “SERIES” for CSAT Previous Articles on Aptitude Rule #1: Maintain a Diary of Mistakes Consider this equation x-33=(17/2) =>2x -33 =17 =>2x=17+33 =>2x=50 hence x=25. Wrong! [...]

## [Aptitude] Alligations,Mixtures,Alloys: Water,Milk,Wine mixing: Weighted Average Made Easy for CSAT,CAT,CMAT,IBPS Aptitude

Easy Wine and Water Mixing Problem Two Solutions: Selling Price of Wine and Profit Dilution by adding Water in the Wine Average Profit / Interest Rate: Jethalal’s Mobile shop Average weight of Group : Gokuldham society’s case Recommended Booklist Previous Articles Introduction Mixture, Alligation [...]

## [Aptitude] Boats and Streams made-easy using our STD-Table Method

Case#1: Basics Case 2: Time same but Different distance covered in each case Case #3: unknown variables Previous Articles I hope you’ve mastered the STD table method from earlier articles on Time and Work / Pipes and Cistern. We can use that STD method even [...]

## [Aptitude] Compound Interest Rate, Population Growth without Formulas

Introduction Case: City’s population: Growth Case: City’s Population: Decline Case: Bank’s compound interest rate(CI) Case: CI →Finding Nemo Principal Case: Compounding Twice a Year Case: Compounding thrice a year Case: Wine Replacement (Adulteration) Approach 1: Alligiation loop Approach #2: Compound Interest Case: Adulteration→Finding [...]

## [Aptitude] Logical Arrangement : Circular / Round Table

Introduction Circular arrangement Step 1: Draw the diagrams Step 2: Run the Checklist Step 3: Proceed with questions Introduction There are 4 types of ‘Logical-Arrangement’ questions Circular : Sitting In a Round Table Linear : Sitting in rectangular table or row Traits: List of people [...]

## [Aptitude] Family Trees & Blood Relations: Logical Arrangement Made Easy

Introduction Dataset #1 Step 1: Gender and Generation table Step 2: Checklist Questions based on the Family-Data Dataset #2: UPSC CSP’2000 Step #1: Gender and Generation table Step-2: Run the checklist Step-3: Solve the Question Do eliminate wrong options Keep a Watch on [...]

## [Aptitude] Partnership and profit-sharing made Easy for CSAT IBPS CAT

Case 1: Two partners join @same time Step 1: Fill up the table Step 2: Find Ratio of Actual investment Step 3: Componendo on Total Profit Case 2: Two Partners join @Different Time Step 1: Fill up table Step 2: Find Ratio of [...]