Mathematics and Stastics

 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 Relative Speed And Train Questions

   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

 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

 Data Sufficiency in Statistics A sufficient statistic is a statistic that summarizes all of the information in a sample about a chosen parameter. For example, the sample mean, x̄, estimates the population mean, μ. x̄ is a sufficient statistic if it retains all of the information about the population mean that was contained … Read more Data Sufficiency In Statistics

     Surds A surd is a square root which cannot be reduced to a rational number. For example,  is not a surd. However  is a surd. If you use a calculator, you will see that  and we will need to round the answer correct to a few decimal places. This makes it less accurate. If … Read more Surds And Indices

 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

   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

 Compound Interest   Let Principal = P, Rate = R% per annum, Time = n years.   When interest is compound Annually:    Amount = P 1 + R n 100 When interest is compounded Half-yearly:     Amount = P 1 + (R/2) 2n 100 When interest is compounded Quarterly:     Amount = … Read more Compound Interest

 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

 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 Calculation Of Income Tax