Average – whether weighted or simple or a different kind – is a simple mathematical concept. The kinds of problems these can be used in are mentioned later. The range of problems can be of the type where every number is changed through addition, multiplication, division, etc. Calculation skills again come in handy. The problems are easier if the number of digits is small but otherwise as well it does not take more than a minute because Vedic Mathematics and other tools allow for such calculations. A lowdown on the kinds of problems and instances of average questions for entrances is:
Kind of problems of average questions for entrances:
- Weighted Average
Weighted average of a group of sets calculates a value that is meant to find out a single value for the entire set. The single value for the sets defines a value such as price among a range of products, average income for different datasets. This can be useful in work related to Indian population wherein it is meant to find out the average income value to make policies reach to different sets.
Example: Allocation made for model village scheme for Member of Parliaments in 2 villages for toilets, computing facility, schools, provision of electricity, etc. is such that for smaller parties having a set of MPs, the average value is 1.5 Crore for a party with 16 MPs and hence 16 villages and 1 Crore for a party with 12 MPs. For these 28 MPs, calculate the average allocation to compare it with that of Pradhan Mantri Narendra Modi’s?
- Problems based on ages
Problems based on ages in a family in combination with links between family members to depict relations as well as ages can be one of the Data Interpretation problem sets. In CAT, this question set can be particularly scoring with 4 marks for each of the five questions. Depending on the difference in number of years and the number of time periods being considered, these questions can be prepared for all kinds of tests.
- Income, expenditure & savings
Expenditure, income & savings make their way even into SNAP, XAT and other B-school entrance tests. This data, again, can be used for mathematical and Data Interpretation questions. In case this information is about multiple people and talks of information giving expenses, the level of difficulty can go beyond that is required for SSC CGL. In data interpretation, this can be of the table form or a pie chart as well.
Example: Problem on comparison of expenditure, income and savings on 3 people A, B and C
- Speed, time & distance
TSD & displacement problems, averages come from the laws of motion with each of these talking of velocity – initial or final – and acceleration. Distance or displacement is another factor that is a part of these equations. For entrance tests, these could just be about two people covering a distance with different speeds and meeting at a point whether person A overtakes or meets the person with each covering the distance towards the other. Questions on relative velocity are also based on the concept of average speeds and motion.
Example: Simple problems can be based on the formula for two and three entities, with speeds being u, v and w. The formulae for these are 2uv/(u+v) and 3uvw / (uv +vw +wu)
- Average of a series of numbers
The series of numbers could be that of natural numbers, their squares and cubes. This series could also be that of first n even or odd numbers.
Example: The problem can be one using other concepts but could use these as part of calculations to make it easier. This can be in Quant as well as DI.
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