Mathematics and Stastics

   TIPS AND TRICKS FOR SPEEDY CALCULATIONS – MODULE IV – DIVISION Division is no more tedious as it used to be! In this module we deal with divisibility rules of various numbers, how to find remainders and general division rules. After reading this module and solving problems by heart you may find … Read more

 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

 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

 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

 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

 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

 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

 Multiplying Fractions There are 3 simple steps to multiply fractions Multiply the top numbers (the numerators).    Multiply the bottom numbers (the denominators).    Simplify the fraction if needed.   example:  1 / 2 ×  2 / 5 =? Step 1  Multiply the top numbers:         1 / 2 ×  2 / 5 = … Read more

 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

 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