Percentage : Types of Questions Asked in Competitive Exams

percentage tricks,percentages

Hello Friends, In this chapter we will go through various " types of questions asked in competitive exams " on percentage in aptitude section.

Type 1 : Problems based on numbers

Question 1. A number on subtracting 35 to it reduces it by 80 %. What is the 20 % of that number ?


Solution : Let the number be X

According to Question,
X - 35 = X ( 80/100 )
=> X - 35 = 8 X / 10
=> 10 X - 350 = 8 X
=> 10 X - 8 X = 350
=> 2 X = 350
=> X = 175
Now, 20 % of 175 = ( 20 /100 ) 175 = 35

Type 2 : Problem based on Students and Marks


Under this, there are two different ways by which questions can be asked in the examination.


Way 1 : A candidate scores x % is an examination fails by ‘a’ marks, while another candidate who scores y % marks and get 'b' marks more than the maximum required passing marks, then the maximum marks for the examination is given by


M = {100 ( a + b ) / ( y - x )}


Question 2 : In a quarterly examination a student secured 30% marks and failed by 15 marks. In the same examination another student secured 40% marks and got 35 marks more than minimum marks to pass. Calculate the maximum marks and the passing marks.


Solution : Maximum marks ( M ) = { 100 ( 15 + 35 ) / ( 40 - 30 ) } = 5000 / 10 = 500


Passing Marks = 30 % of 500 + 15 or 40 % of 500 - 35


Way 2 : In an examination a % of total number of candidates failed in a subject X and b % of total number of candidates failed in subject Y and c % failed in both subjects, then percentage of candidates, who passed in both the subjects, is [100 – (a + b – c)] %


Question 3 : In an examination, 42 % of the candidates failed in English and 52 % failed in Mathematics. If 17 % failed in both the subjects, then find the percentage of candidates who passed in both the subjects.


Solution : Percentage of candidates, who passed in both the subjects, is [100 – (a + b – c)] %


Thus, Percentage of candidates, who passed in both the subjects = [ 100 - ( 42 + 52 - 17 ) ] % = 23 %


Type 3 : Problems based on Depreciation


Question 4 : The value of a printing machine depreciates at the rate of 20 % per annum. If the cost of machine at present is Rs. 60,000, then what will be its worth after 2 years ?


Solution : In this type of problem we will use the formula 


Price of goods after n years = Present Price { 1 - ( Rate / 100 ) } n


Thus, Price of printing machine after 2 years = 60000 { 1 - ( 20 / 100 ) } 2


= 60000 { 4 / 5 } 2 = 60000 ( 16 / 25 ) = 38400


Type 4 : Problem based on population


Under this, there are two different ways by which questions can be asked in the examination.


Way 1 : If the current population of a city is X and the rate of increase in population is Y then population after n years is given by formula : X { 1 + ( Y / 100 )  } n


Question 5 : The current population of a city is 60000. Find the population of city after 2 years if the rate of increase in population is 20 %.


Solution : Population after 2 years = 60000 { 1 + ( 20 / 100 ) 2


= 60000 { 6 / 5 } 2 = 60000 ( 36 / 25 ) = 86400


Way 2 : If the current population of a city is X and the rate of increase in population is Y then population n years ago is given by formula : X / { 1 + ( Y / 100 )  } n


Question 6 : The current population of a city is 60000. Find the population of city 2 years ago if the rate of increase in population is 20 %.


Solution : Population 2 years ago = 60000 / { 1 + ( 20 / 100 ) 2


= 60000 / { 6 / 5 } 2 = 60000 / ( 36 / 25 ) = 41667


Type 5 : Problem based on price of goods or services


Under this, there are two different ways by which questions can be asked in the examination.


Way 1 : If the price of goods increases by R %, then the reduction in consumption so as not to increase the expenditure can be calculated using the formula :


{ R / ( 100 + R) } x 100 %


Question 7 : The price of diesel increases by 25 %. Find by how much percent a truck owner must reduce his consumption in order to maintain the same budget ?


Solution : { 25 / ( 100 + 25 ) } x 100 % = 20 %


Way 2 : If the price of goods decreases by R %, then the increase in consumption so as not to decrease the expenditure can be calculated using the formula :


{ R / ( 100 - R) } x 100 %


Question 8 : The price of rice falls by 25 %. By what percentage a person can increase the consumption of rice so that his overall budget does not change ?


Solution : { 25 / ( 100 - 25 ) } x 100 % = 33.33 %


At last, Thanks for choosing Loud Study.


Please comment in comment section below if you have any doubt or query. We will try to resolve it as soon as possible.

No comments

We appreciate your comment! You can either ask a question or review our blog. Thanks!!