Variance

Variance Variance (?2) in statistics is a measurement of the spread between numbers in a data set. That is, it measures how far each number in the set is from the mean and therefore from every other number in the set. In investing, the variance of the returns among assets in a portfolio is analyzed … Read more Variance

Contribution Of Aryabhatta In Mathematics

? Contribution of aryabhatta in mathematics Number notation Numerical values He made a notation system in which digits are denoted with the help of alphabet numerals e.g., 1 = ka, 2 = Kha, etc. Aryabhatta assigned numerical values to the 33 consonants of the Indian alphabet to represent 1,2,3…25,30,40,50,60,70,80,90,100. Notation system  He invented a … Read more Contribution Of Aryabhatta In Mathematics

Tips And Tricks For Speedy Calculations Module 2 Roots

?   TIPS AND TRICKS FOR SPEEDY CALCULATIONS – MODULE III – MULTIPLICATION In this module we deal with techniques using which we can multiply two numbers in an unorthodox but quick manner. Firstly we take up some specific cases using which we come to generalized multiplication of any two given numbers. Multiplying two … Read more Tips And Tricks For Speedy Calculations Module 2 Roots

Age Problems

? Age Problems   Important Formulas on “Problems on Ages”:   1. If the current age is x, then n times the age is nx. 2. If the current age is x, then age n years later/hence = x + n. 3. If the current age is x, then age n years ago = x – n. 4. The ages in a ratio a : b will be ax and bx. 5. If the current age is x, … Read more Age Problems

Average Or Ap

? Average   What is Average? The result obtained by adding several quantities together and then dividing this total by the number of quantities is called Average. The main term of average is equal distribution of a value among all which may distribute persons or things. We obtain the average of a number using formula that … Read more Average Or Ap

Simple Interest

? MATHEMATICS AND QUATITUATIVE APTITUDE – SIMPLE INTEREST Introduction Money is not free and it costs to borrow the money. Normally, the borrower has to pay an extra amount in addition to the amount he had borrowed. i.e, to repay the loan, the borrower has to pay the sum borrowed and the interest. Lender … Read more Simple Interest

Percentage

?          Important Formulas – Percentage Percentage Percent means for every 100 So, when percent is calculated for any value, it means that we calculate the value for every 100 of the reference value. percent is denoted by the symbol %. For example, x percent is denoted by x% x%=x/100 Example : … Read more Percentage

Direction Test

? Direction test     Introduction: There are four main directions – East, West, North and South as shown below:         There are four cardinal directions – North-East (N-E), North-West (N-W), South-East (S-E), and South-West (S-W) as shown below:       Key points   At the time of sunrise if a man stands facing the east, his shadow will be towards … Read more Direction Test

Number System

? Number system 1. Basic Formulae  (a + b)(a – b) = (a2 – b2) (a + b)2 = (a2 + b2 + 2ab) (a – b)2 = (a2 + b2 – 2ab) (a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca) (a3 + b3) = (a + b)(a2 – ab + b2) (a3 – b3) = (a – b)(a2 + ab + b2) (a3 + b3 + c3 – 3abc) = (a + b + c)(a2 + b2 + c2 – ab – bc – ac) When a + b + c = 0, then a3 + b3 + c3 = 3abc   2. Types of Numbers I. Natural Numbers Counting numbers 1,2,3,4,5,…1,2,3,4,5,… are called natural numbers   … Read more Number System

Puzzle Test

? Puzzle Test Puzzle Test section comprises problems put in the form of puzzles involving certain number of items, be it persons or things. The candidate is required to analyse the given information, condense it in a suitable form and answer the questions asked.     In this type of test, the questions are … Read more Puzzle Test

Data Interpretation

? Data interpretation Data Interpretation or DI refers to the implementation of procedures through which data is reviewed for the purpose of arriving at an inference. Data can be obtained from multiple sources e.g. data from running of industries, census population data etc. Interpreting data requires analyzing data to infer information from it in … Read more Data Interpretation

Vedic Maths

? Vedic maths: Square Example : Find square of   12 Step 1 1010 is the nearest power of 1010 which can be taken as our base. The deviation to our base =12?10=2=12?10=2 (To find the deviation, just remove the leftmost digit “11” and you will get it quickly). Left side of the answer is the sum of the number … Read more Vedic Maths

Banking

? Commercial mathematics Banking Banking can be defined literarily as the business activity of accepting and safeguarding money owned by individuals and entities and release of the money whenever the needs arise by the owner. It is the business of managing money and where money is involved everything must be carefully assessed, valued and … Read more Banking

ClassificationL 1

? Analogy Level-1   CLASSIFICATION LEVEL 1 Classification involves putting things into a class or group according to particular characteristics so it’s easier to make sense of them, whether you’re organizing your shoes, your stock portfolio, or a group of invertebrates.  From all competitive examination classification is one of the most important topics, this … Read more ClassificationL 1

Area Of Triangle

? Area of triangle The area of triangles can be found by using the following formula:                         Area =  Base × height / 2 The red line represents the length of the base (call it b if you want) and the blue line represents the length of the height.   To get the area, … Read more Area Of Triangle

Chain Rule

? CHAIN RULE This module will teach you the basics of direct and indirect proportions. These concepts will further help you in time and work questions. Important Formulas – chain rule Direct Proportion Two quantities are said to be directly proportional, if on the increase or decrease of … Read more Chain Rule

Shrinivas Ramanujan

? Shrinivas Ramanujan: Contribution to mathematics Srinivasa Ramanujan, an Indian mathematician was born in 22nd December, 1887 in Madras, India. Like Sophie Germain, he received no formal education in mathematics but made important contributions to advancement of mathematics. His chief contribution in mathematics lies mainly in analysis, game theory and infinite series. He made … Read more Shrinivas Ramanujan

Median

? Median Median is the middle number in a sorted list of numbers. To determine the median value in a sequence of numbers, the numbers must first be arranged in value order from lowest to highest. If there is an odd amount of numbers, the median value is the number that is in the … Read more Median

Fractions

? Fractions Any unit can be divided into any numbers of equal parts, one or more of this parts is called fraction of that unit. e.g. one-forth (1/4), one-third (1/3), three-seventh (3/7) etc. The lower part indicates the number of equal parts into which the unit is divided, is called denominator. The upper part, which indicates the number … Read more Fractions

Averages

? Average The word “average” is used in everyday life to describe where the middle number of a data set is. It’s the typical number you would expect to find in a series of numbers. In statistics, the average is called the “arithmetic mean,” usually just shortened to the mean. Both the average and … Read more Averages

Time & Work

? TIME AND WORK In these problems the number of persons, quantity of work done and time taken are important factors. Also time taken by a person depends on the efficiency of that person which comes into picture when different people do the work such as women, children do the work … Read more Time & Work

Pie

? Pie-chart A pie graph (or pie chart) is a specialized graph used in statistics. The independent variable is plotted around a circle in either a clockwise direction or a counterclockwise direction.The dependent variable (usually a percentage) is rendered as an arc whose measure is proportional to the magnitude of the quantity.Each arc is … Read more Pie

Simplification

? Simplification Simplification is one of the most important part of Quantitative Aptitude section of any competitive exam. Today I am sharing all the techniques to solve Simplification questions quickly. Rules of Simplification V ? Vinculum B ? Remove Brackets – in the order ( ) , { }, [ ]  O ? Of D ? Division M … Read more Simplification

Algorithm Method

? Algorithm method – meaning and quality, indefinate, definite In mathematics, computing, linguistics and related subjects, an algorithm is a sequence of finite instructions, often used for calculation and data processing. It is formally a type of effective method in which a list of well-defined instructions for completing a task will, when given an … Read more Algorithm Method

Mensuration (revised)

? MENSURATION Mensuration is the branch of mathematics which deals with the study of different geometrical shapes, their areas and Volume. In the broadest sense, it is all about the process of measurement. It is based on the use of algebraic equations and geometric calculations to provide measurement data regarding the width, depth and volume … Read more Mensuration (revised)

Hcf And Lcm

?  HCF & LCM HCF & LCM are acronym for words, Highest common factor and Lowest common multiple respectively. 1. H. C. F While we all know what a multiplication is like 2 * 3 = 6. HCF is just the reverse of multiplication which is known as Factorization. Now factorization is breaking … Read more Hcf And Lcm

Change Of Binary Number To Decimal Number And Decimal Number To Binary Number

? Change of binary number to decimal number and decimal number to binary number Binary Number System Digital computer represents all kinds of data and information in the binary system. Binary Number System consists of two digits 0 and 1. Its base is 2. Each digit or bit in binary number system can be … Read more Change Of Binary Number To Decimal Number And Decimal Number To Binary Number

Tips And Tricks For Speedy Calculations Module 3 Multiplication

?   TIPS AND TRICKS FOR SPEEDY CALCULATIONS – MODULE III – MULTIPLICATION In this module we deal with techniques using which we can multiply two numbers in an unorthodox but quick manner. Firstly we take up some specific cases using which we come to generalized multiplication of any two given numbers. Multiplying two … Read more Tips And Tricks For Speedy Calculations Module 3 Multiplication

Discounts

? Discount   The discount is referred to the reduction in the price of some commodity or service. It may anywhere appear in the distribution channel in the form of modifications in marked price (printed on the item) or in retail price (set by retailer usually by pasting a sticker on the item) or in list price (quoted for the buyer). The discount … Read more Discounts

AnalogyLevel1

? Analogy Level-1 ANALOGY LEVEL 1 When you draw an analogy between two things we compare them for the purpose of explanation. If a scientist says that earth’s forest functions as human lungs then we instantly draw an explanation that both lungs and trees intake important elements from air. As far as SSC … Read more AnalogyLevel1

Prepositions

? Prepositions Prepositions are short words (on, in, to) that usually stand in front of nouns (sometimes also in front of gerund verbs). Even advanced learners of English find prepositions difficult, as a 1:1 translation is usually not possible. One preposition in your native language might have several translations depending on the situation. The … Read more Prepositions

Partnership

? PARTNERSHIP   Partnership : Partnership is an association of two or more parties, they put money for business.         Simple Partnership: Simple partnership is one in which the capitals of the partners are invested for the same time. The profit or losses are divided among the partners in the ratio … Read more Partnership