Mathematics and Stastics

 Concepts of geometry Points, Lines & Planes   The most fundamental geometric form is a point. It is represented as a dot with a capital alphabet which is its name. A line is a set of points and it extends in opposite directions up to infinity. It is represented by two points on … Read more

 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

 Pipes and Cistern   Inlet: A pipe connected with a tank or a cistern or a reservoir, that fills it, is known as an inlet.   Outlet: A pipe connected with a tank or cistern or reservoir, emptying it, is known as an outlet.   If a pipe can fill a tank in x hours, … Read more

 Calculation of income tax (for salaried person and excluding house rent allowance) Salary is made up of various components such as:   Basic salary,    House rent allowance (HRA),   Special allowance Other allowances, reimbursements etc.   However, not all of the amount received as salary is fully taxable. A part of it … Read more

 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

 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

   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

 Height and Distance This topic has many practical application in day to day life. In engineering stage it is used in surveying. The basic purpose is to find the unknown variables by observing the angle of the line of sight. This is done by using some the fact that in … Read more

 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

 RELATIVE SPEEED AND TRAIN QUESTIONS Speed has no sense of direction unlike the velocity. Relative speed is the speed of one object as observed from another moving object. Questions on train are the classic examples of relative speed and in all these questions it is assumed that trains move parallel … Read more