Question

The cost of $11$ pencils and $3$ erasers is Rs. $50$ and the cost of $8$ pencils and $3$ erasers is Rs. $38$. Find the cost of each pencil and each eraser.

Answer 1

Let x denote the cost of a pencil in rupees and y denote the cost of an eraser in rupees. Then according to the given information we have

$11x+3y=50$ (1)

$8x+3y=38$ (2)

Subtracting (2) from (1) we get, x 3 = 12 which gives 4 = x .

Now substitute x = 4 in (1) to find the value of y. We get,

$11\left(4\right)+3y=50$ i.e., y=2

Therefore,x=4 and y = 2 is the solution of the given pair of equations.

Thus, the cost of a pencil is Rs. 4 and that of an eraser is Rs. 2.