Percentage calculation on population Shortcut Tricks


Percentage calculation on population Shortcut Tricks

Shortcut Tricks are very important things in competitive exam. Time is the main factor in competitive exams. If you know how to manage time then you will surely do great in your exam. Most of us miss this thing. Here in this page we give few examples on Percentage calculation on population shortcut tricks. These shortcut tricks cover all sorts of tricks on Percentage calculation on population. Visitors please read carefully all shortcut examples. These examples here will help you to better understand shortcut tricks on percentage calculation on population.

First of all do a practice set on math of any exam. Then find out twenty math problems related to this topic and write those on a paper. Do first ten maths using basic formula of this math topic. You also need to keep track of timing. Write down the time taken by you to solve those questions. Now go through our page for percentage calculation on population shortcut trick. After finishing this do remaining questions using Percentage calculation on population shortcut tricks. Again keep track of Timing. The timing will be surely improved this time. But this is not all you need. You need to practice more to improve your timing more.

We all know that the most important thing in competitive exams is Mathematics. It doesn’t mean that other topics are not so important. But only math portion can leads you to a good score. Only practice and practice can give you a good score. You should do your math problems within time with correctness, and only shortcut tricks can give you that success. But it doesn’t mean that without using shortcut tricks you can’t do any math problems. You may do math problems within time without using any shortcut tricks. You may have that potential. But so many other people may not do the same. Here we prepared percentage calculation on population shortcut tricks for those people. Here in this page we try to put all types of shortcut tricks on Percentage calculation on population. But we may miss few of them. If you know anything else rather than this please do share with us. Your help will help others.

Percentage is a very important chapter and it uses most chapters for calculation.Shortcut Tricks is based on, to find the population of a particular town,city in increased and decreased order that is obtain in this type of questions.

we go through the shortcut tricks. This type of problem are given in Quantitative Aptitude which is a very essential paper in banking exam.Under below  given some more example for your better practice.

when we say 100 percent in mathematical notation we write 100% so, 35 % means 35 per 100 and 65% means 65 per 100 it is a proportion per hundred and it is used to find marks percentage of a student, profit percent or loss percent of a particular product.

It is also used in find out the depreciation at the rate percent per annul or population of a particular city or town where due to some reason rate of population increases or decreases.

we can expressed ration number as percent, Here is some different percent related problems are given with shortcut tricks below.

 

 

Example #1
The population of a village is 2500. It decreases by 4% in the first year and increases by 3% in the second year. What is the population at the end of two years?

Answer
First year decreases by 4% = 2500 x 96 /100 = 2400.
Second year increases by 3% = 2400 x 103 / 100 = 2472.

Shortcut Tricks
2500 x 96 x 103 / 100 x 100
= 2472.

 

Example #2
The population of a city is 175000. In the first year it decreases by 6% and in the second year it increases by 8%. What would be the population of the city at end of the years?

Answer
175000 x 94 x 108 / 100 x 100
= 177660.

 

Example #3
The population of a town has rapidly increases by 20% every year. If the population of the town in 2014 was 600000 then, What would be it’s population in 2017 ?

Answer
Population in that town in 2017
600000 x 120 x 120 x 120 / 100 x 100 x 100
= 1036800.

 

Example #4
In a town has present population 52500 and if it is decreased by 20% per year then What would be the population of the town after 2 years?

Answer
We know, Population after n year = P(1 – R/100)n
So, Here P = 52500
R = 20% ( decreased )
n = 2 years.

Population after 2 years
52500 x (1 – 20/100)2
= 52500 x (4/5)2
= 52500 x 0.64
= 33600

Shortcut Tricks
= 52500 x 80/100 x 80/100
= 33600.

 

Example #5
The population of a city was 24000 two years ago. Population decreases every year at the rate of 5%. Find the present population of the city.

Answer
Present population of that city is
= 24000 x ( 1 – 5% )2
=24000 x ( 1 – 5 / 100 )2
=24000 x ( 19 / 20 x 19 / 20 )
=21660.

 

Example #6
The population in Pune city was 150000 three years ago. If it increased by 4%, 5% and 6% respectively in the last three years, then Find the present population of the Pune city?

Answer
Here population increased by continuous three years respectively, So Present population is the city is
= 150000 x (1 + 4 / 100 ) x ( 1 + 5 / 100 ) x ( 1 + 6 / 100 )
= 150000 x 104 / 100 x 105 / 100 x 106 / 100
= 150000 x 52 x 21 x 106 / 50 x 20 x 100
= 173628.

 

Example #7
The population of a town increased by annually 6%. If it’s population in 2016 is 1356800. Then, what would be it’s population in 2017 ?

Answer
1356800 x 106 / 100 = 1438208.

 

Example #8
60% of the population of a city are men and 15% are women. If the number of children are 20000, then how many men’s are their in the city?

Answer
25% = 20000
60% = 20000 x 60 / 25 = 48000.

 

Example #9
The total population of a village is 6000. The number of males and females increases by 10% and 20% respectively and consequently the population of the village becomes 7500. What was the number of males in the village?

Answer
The total % increased population
= 7500 – 6000 x 100 / 6000
= 1500 x 100 / 6000 = 25%
By allegation method
Male         Female
+10             +20

       +25

5                15

Male population before increment
= 6000 x 5 / 20 =   1500

 

Example #10
The population of a town is 56600. If on the 1st year it is decreased by 10% and 2nd year it is increased by 20%. What would be the population of that city after 2 years?

Answer
56600 x 90 x 120 / 100 x 100 = 61128
So, after 2 years the population of that city is 61128.

 

Example #11
The population of a city increases by 10% annually. If its population in 2017 was 12000 then, What it was in 2014 ?

Answer
We need to find the population of city 3 years back, and also the population of a city increases by 10% annually.
So, In 2014 the population of city was
= 12000 / (1 + 10%)3
= 12000 x ( 22 / 20 x 22 / 20 x 22 / 20 )
= 15972.

 

Example #12
If in a city every year population is decreased by 6%, What would be after 2 years of this town’s population while it’s present population is 65000.

Answer
65000 x 94 x 94 / 100 x 100 = 57434.

 

Example #13
The population of a city has increased continually from 171000 to 256500 in a decades. Find the average percentage increases of that city yearly.

Answer
( 256500 – 171000 ) = 85500.
% = 85500 x 100 / 171000 = 50%.

Average is (50 / 10)% = 5%

 

 
Percentage calculation on population Shortcut Tricks

 

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11 comments

  1. suji says:

    Eg:11 uses formula for percentage increase in population n years ago. but while doing calculation i can see that formula for population after n years is used…

  2. arish says:

    Please solve my this question:-
    A. The population of a city increases 15% annually. If the present population is 20,700 , find the population an year ago..

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