Mathematics and Stastics

 BOAT AND STREAM Boat and stream problems is a sub-set of time, speed and distance type questions where in relative speed takes the foremost role. We always find several questions related to the above concept in SSC common graduate level exam as well as in bank PO exam. Upon listing … Read more Boat And Stream

 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

 Distance between two points Here is how to calculate the distance between two points when you know their coordinates:     Let us call the two points A and B     We can run lines down from A, and along from B, to make a Right Angled Triangle. And with a little … Read more Distance Between Two Points

 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

 Profit and loss   IMPORTANT FACTS Cost Price: The price, at which an article is purchased, is called its cost price, abbreviated as C.P.   Selling Price: The price, at which an article is sold, is called its selling prices, abbreviated as S.P.   Profit or Gain: If S.P. is greater than C.P., the seller is said … Read more Profit Loss

 HCM and LCM Factors A factor of a number are all those numbers, which exactly divide the given number. “Exactly divides” means that when a number is divided by its factor the reminder is always  0. For example: 1,2,and 4 are the factors of 4. Multiples Multiples of a number are those numbers … Read more HCM And LCM And Time And Work

 Vedic Mathematics Vedic Mathematics is a collection of Techniques/Sutras to solve mathematical arithmetics in easy and faster way. It consists of 16 Sutras (Formulae) and 13 sub-sutras (Sub Formulae) which can be used for problems involved in arithmetic, algebra, geometry, calculus, conics. Some vedic maths trics  Multiply a number by 9   Multiply … Read more Vedic Mathematics

 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

 Mixed ratio and proportion Ratio Introduction: Ratio is the relation which one quantity bears to another of the same kind. The ratio of two quantities a and b is the fraction a/b and we write it as a: b. In the ratio a: b, we call a as the first term or antecedent and b, … Read more Mixed Ration And Proportion