Question

The cost of $2$ pencil, $4$ pens and $8$ erasers is $Rs.12$ and the cost of $8$ pens, $10$ pencils and $4$ erasers is $Rs.36$. How much will $3$ pencils, $3$ pens and $3$ erasers cost?

• A. $18$
• B. $15$
• C. $12$
• D. $10$

Answer 1

The correct option is C $12$

Let the cost of $1$ pencil, $1$ pen and $1$ eraser be $x,y,$ and $z$ respectively.

$2x+4y+8z=\mathrm{12....}\left(1\right)$
$10x+8y+4z=\mathrm{36....}\left(2\right)$

Adding $\left(1\right)$ and ($2)$, $12x+12y+12z=48$

$\Rightarrow 3x+3y+3z=\frac{48}{4}=12$

$\therefore$ Cost of $3$ pencil, $3$ pens and $3$ eraser is $Rs.12$