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

 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

 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

 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

   TIPS AND TRICKS FOR SPEEDY CALCULATIONS – MODULE I – SQUARES In this module we deal with finding squares of two digit and three digit numbers and some special cases arising out of these forms. This section is not only important in itself but forms the very basis of more tedious and … Read more

 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

 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

 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

 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

Variance Variance (σ2) 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