Answer
396.9k+ views
Hint: We assume the salary of one of the people as a variable and use the sum to form an equation for the salary of the second person. Calculate the saving percentage by subtracting the percentage of spending from 100. Equate the percentage of savings of each person multiplied with their respective salary and equate them.
* We calculate the percentage of a number x as \[\dfrac{m}{{100}} \times x\].
Complete step-by-step solution:
Let us assume the salary of Ajay as \[x\]
The sum of salaries of Ajay and Vijay is Rs.12,000.
Then we can write salary of Vijay will be \[12000 - x\]
Now we are given Ajay spends 80% of his salary, then Ajay saves \[\left( {100 - 80} \right)\% = 20\% \] of his salary.
Since we have salary of Ajay as \[x\]
Then using concept of percentage we can calculate the amount saved by Ajay
\[ \Rightarrow \]Savings made by Ajay \[ = 20\% \times (x)\]
\[ \Rightarrow \]Savings made by Ajay \[ = \dfrac{{20}}{{100}}x\].................… (1)
Similarly Vijay spends 90% of his salary, then Vijay saves \[\left( {100 - 90} \right)\% = 10\% \]of his salary.
Since we have salary of Vijay as \[12000 - x\]
Then using concept of percentage we can calculate the amount saved by Vijay
\[ \Rightarrow \]Savings made by Vijay \[ = 10\% \times (12000 - x)\]
\[ \Rightarrow \]Savings made by Vijay \[ = \dfrac{{10}}{{100}}(12000 - x)\].............… (2)
Now we are given that they both have the same savings.
So, we equate the savings from both equations (1) and (2)
\[ \Rightarrow \dfrac{{20}}{{100}}x = \dfrac{{10}}{{100}}(12000 - x)\]
Cancel same factors from denominator on both sides of the equation
\[ \Rightarrow 20x = 10(12000 - x)\]
Cancel same factors from both sides i.e. 10
\[ \Rightarrow 2x = 12000 - x\]
Bring all variables to LHS of the equation
\[ \Rightarrow 2x + x = 12000\]
\[ \Rightarrow 3x = 12000\]
Cancel same factors from both sides i.e. 3
\[ \Rightarrow x = 4000\]
So, salary of Ajay is Rs.4000
We can calculate salary of Vijay as \[12000 - 4000 = 8000\]
So, salary of Vijay is Rs.8000
\[\therefore \]Option C is correct.
Note: Many students make the mistake of calculating the money spent as we are given a percentage of money spent. Then they subtract the money from assumed variables which exceeds the calculation and solution becomes lengthy and complex. We are given savings equal so we have to form an equation of savings.
* We calculate the percentage of a number x as \[\dfrac{m}{{100}} \times x\].
Complete step-by-step solution:
Let us assume the salary of Ajay as \[x\]
The sum of salaries of Ajay and Vijay is Rs.12,000.
Then we can write salary of Vijay will be \[12000 - x\]
Now we are given Ajay spends 80% of his salary, then Ajay saves \[\left( {100 - 80} \right)\% = 20\% \] of his salary.
Since we have salary of Ajay as \[x\]
Then using concept of percentage we can calculate the amount saved by Ajay
\[ \Rightarrow \]Savings made by Ajay \[ = 20\% \times (x)\]
\[ \Rightarrow \]Savings made by Ajay \[ = \dfrac{{20}}{{100}}x\].................… (1)
Similarly Vijay spends 90% of his salary, then Vijay saves \[\left( {100 - 90} \right)\% = 10\% \]of his salary.
Since we have salary of Vijay as \[12000 - x\]
Then using concept of percentage we can calculate the amount saved by Vijay
\[ \Rightarrow \]Savings made by Vijay \[ = 10\% \times (12000 - x)\]
\[ \Rightarrow \]Savings made by Vijay \[ = \dfrac{{10}}{{100}}(12000 - x)\].............… (2)
Now we are given that they both have the same savings.
So, we equate the savings from both equations (1) and (2)
\[ \Rightarrow \dfrac{{20}}{{100}}x = \dfrac{{10}}{{100}}(12000 - x)\]
Cancel same factors from denominator on both sides of the equation
\[ \Rightarrow 20x = 10(12000 - x)\]
Cancel same factors from both sides i.e. 10
\[ \Rightarrow 2x = 12000 - x\]
Bring all variables to LHS of the equation
\[ \Rightarrow 2x + x = 12000\]
\[ \Rightarrow 3x = 12000\]
Cancel same factors from both sides i.e. 3
\[ \Rightarrow x = 4000\]
So, salary of Ajay is Rs.4000
We can calculate salary of Vijay as \[12000 - 4000 = 8000\]
So, salary of Vijay is Rs.8000
\[\therefore \]Option C is correct.
Note: Many students make the mistake of calculating the money spent as we are given a percentage of money spent. Then they subtract the money from assumed variables which exceeds the calculation and solution becomes lengthy and complex. We are given savings equal so we have to form an equation of savings.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why Are Noble Gases NonReactive class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
At which age domestication of animals started A Neolithic class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write a letter to the principal requesting him to grant class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)