Question

Reena has pens and pencils which together are $40$ in number. If she has $5$ more pencils and $5$ less pens, the number of pencils would become $4$ times the number of pens. Find the original number of pens and pencils.

Answer 1

Let number of pens =$x$

And number of pencils =$y$

$\Rightarrow x+y=40$

$\Rightarrow (5+y)+(x-5)=4x$

$\Rightarrow 3x=y$

Substituting in above equations ;

$\Rightarrow x+3x=40$

$\Rightarrow x=10$

$\Rightarrow y=30$

$\therefore$number of pens =$x=10$

$\Rightarrow$number of pencils =$y=30$