Question

Amrita was very fond of reading books. So, she went to the National Book fair at Pragati Maidan in New Delhi to get some story books and text books. When her friends asked her how many of each she had bought, she answered, four times the number of text books is six more than thrice the number of story books. Also, seven times the number of text books added to thrice the number of story books gives 27. (A) Taking the number of text books and story books bought by Amrita as x and y respectively, the pair of linear equations formed in this case is: (a) 4x + 3y = 6; 7x + 3y = 27 (b) 4x-3y=-6; 7x + 3y = 27 (c) 4x - 3y = 6; 7x + 3y = 27 (d) 4x - 3y = 6; 7x - 3y = 27​

Answer 1

Given: the books bought by Amrita is four times the number of text books is six more than thrice the number of storybooks. Also, seven times the number of textbooks added to thrice the number of storybooks gives 27.

To find: the pair of linear equations formed.

Solution:

Take the number of textbooks and storybooks bought by Amrita as x and y respectively.

Form the required equations.

• Four times the number of textbooks i.e.,  $(4x)$ is six more than thrice the number of storybooks i.e., $(6+3y)$

            $4x=6+3y$

           $\[ \Rightarrow 4x - 3y = 6\]$

• Seven times the number of text books i.e., $(7x)$ added to thrice the number of storybooks i.e., $(3y)$ gives 27.

           $\[7x + 3y = 27\]$

Therefore, the equation formed are  $\[ 4x - 3y = 6\]$ and $\[7x + 3y = 27\]$ respectively.

Hence, the correct answer is option (c). i..e, $4x - 3y = 6; 7x + 3y = 27$.

Answer 2

Answer:

let x = textbook y = story book

4x=3y=6

4x-3y=6 (from the question) -(1)

7x+3y=27 (from the question) -(2)

4x-3y=6

7x-3y=27 (elimination method)

11x = 33

x= 33/11 = 3

x=3 in (1)

4x-3y=6

4(3)-3y=6

12-3y=6

-3y= 6-12

-3y = -6

3y = 6 (negative sign gets cancelled)

y= 6/3, y=2.

Hope u understood!