Question

Question 4
The cost of 4 pens and 4 pencils boxes is Rs.100. there times the cost of a pen is Rs. 15 more than the cost of a pencil box,. Form the pair of linear equations for the above situation. Find the cost pen and a pencil box be Rs. y.

Answer 1

Let the cost of a pen be Rs. x and the cost of a pencil box be Rs. y
Then, by given condition
4x + 4y = 100 $\Rightarrow$ x + y = 25
And 3x = y + 15
$\Rightarrow$ 3x – y = 15
On adding Eqs. (i) and (ii), we get
4x = 40
$\Rightarrow$ x = 10
By substituting x = 10, in Eq. (i) we get
Hence, the cost of a pen and a pencil box are Rs. 10 and Rs. 15, respectively