Answer
Verified
480.3k+ views
Hint: In this question assume any variable be the population of village 2 years ago, then apply the concept that if p% population is decreased from present population say (q), then the present population becomes $\left( {q - \dfrac{p}{{100}}q} \right)$ so, use this concept to reach the solution of the question.
Let the population of the village 2 years ago be x.
Now it is given that the first year it was decreased by 6% due to migration, poverty and unemployment.
So, we have to subtract 6% of x from x, to get the population this year, let the population this year be y.
$ \Rightarrow y = x - \dfrac{6}{{100}}x$…………… (1)
Now next year the population of the village which is y now and it is decreased by 4% due to migration, poverty and unemployment, so we have to subtract 4% of y from y, let the population this year be z.
$ \Rightarrow z = y - \dfrac{4}{{100}}y$…………… (2)
Now it is also given that the population this year was $315,840$.
$ \Rightarrow z = 315,840$
Now from equation (2) we have,
$315,840 = y - \dfrac{4}{{100}}y$
$
\Rightarrow 315,840 = y - \dfrac{4}{{100}}y \\
\Rightarrow 315,840 = y - \dfrac{1}{{25}}y \\
\Rightarrow 315,840 = \dfrac{{24}}{{25}}y \\
\Rightarrow y = \dfrac{{315,840 \times 25}}{{24}} = 13,160 \times 25 = 329,000 \\
$
Now from equation (1) we have
$
329,000 = x - \dfrac{6}{{100}}x \\
\Rightarrow 329,000 = x - \dfrac{3}{{50}}x \\
\Rightarrow 329,000 = \dfrac{{47}}{{50}}x \\
\Rightarrow x = \dfrac{{329,000 \times 50}}{{47}} = 7000 \times 50 = 350,000 \\
$
So, the required population of the village 2 years ago is 350,000.
Note: In such types of questions remember that the data given in question is that the present population of the village is $315,840$ and Last year the migration was 4% and the year before last, it was 6% , so let the population of the village 2 years ago be x and this year the population is decreased by 6% and next year the population is decreased by 4% now construct the equations as above according to given information and simplify, we will get the required population 2 years ago.
Let the population of the village 2 years ago be x.
Now it is given that the first year it was decreased by 6% due to migration, poverty and unemployment.
So, we have to subtract 6% of x from x, to get the population this year, let the population this year be y.
$ \Rightarrow y = x - \dfrac{6}{{100}}x$…………… (1)
Now next year the population of the village which is y now and it is decreased by 4% due to migration, poverty and unemployment, so we have to subtract 4% of y from y, let the population this year be z.
$ \Rightarrow z = y - \dfrac{4}{{100}}y$…………… (2)
Now it is also given that the population this year was $315,840$.
$ \Rightarrow z = 315,840$
Now from equation (2) we have,
$315,840 = y - \dfrac{4}{{100}}y$
$
\Rightarrow 315,840 = y - \dfrac{4}{{100}}y \\
\Rightarrow 315,840 = y - \dfrac{1}{{25}}y \\
\Rightarrow 315,840 = \dfrac{{24}}{{25}}y \\
\Rightarrow y = \dfrac{{315,840 \times 25}}{{24}} = 13,160 \times 25 = 329,000 \\
$
Now from equation (1) we have
$
329,000 = x - \dfrac{6}{{100}}x \\
\Rightarrow 329,000 = x - \dfrac{3}{{50}}x \\
\Rightarrow 329,000 = \dfrac{{47}}{{50}}x \\
\Rightarrow x = \dfrac{{329,000 \times 50}}{{47}} = 7000 \times 50 = 350,000 \\
$
So, the required population of the village 2 years ago is 350,000.
Note: In such types of questions remember that the data given in question is that the present population of the village is $315,840$ and Last year the migration was 4% and the year before last, it was 6% , so let the population of the village 2 years ago be x and this year the population is decreased by 6% and next year the population is decreased by 4% now construct the equations as above according to given information and simplify, we will get the required population 2 years ago.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Mark and label the given geoinformation on the outline class 11 social science CBSE
When people say No pun intended what does that mea class 8 english CBSE
Name the states which share their boundary with Indias class 9 social science CBSE
Give an account of the Northern Plains of India class 9 social science CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths
In Indian rupees 1 trillion is equal to how many c class 8 maths CBSE
Which are the Top 10 Largest Countries of the World?
How do you graph the function fx 4x class 9 maths CBSE
Give 10 examples for herbs , shrubs , climbers , creepers
Difference Between Plant Cell and Animal Cell
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Why is there a time difference of about 5 hours between class 10 social science CBSE