Question

The cost of $7$ erasers and $5$ pencils is Rs.$58$ and the cost of $5$ erasers and $6$ pencils is Rs.$56$. Formulate this problem algebraically and solve it graphically.

Answer 1

Let the cost of one eraser be $x$ and pencil be $y$

Cost of $7$ eraser and $5$ pencils is $58$

$\Rightarrow 7x+5y=\mathrm{58........}\left(i\right)$

Cost of $5$ erasers and $6$ pencils is $56$

$\Rightarrow 5x+6y=56$

Solving $\left(i\right)$ and $\left(ii\right)$

$\Rightarrow x=4,y=6$

So cost of one eraser is $Rs.4$ and pencil is $Rs.6$