Question

A person spent $Rs564$ in buying pens and pencils if cost of each pen is $Rs.7$ and each pencil is $Rs.3$ and if the total number of things bought was $108$, how many of each type did he buy?

Answer 1

$\Rightarrow$ Let the number of pens be $x.$

$\Rightarrow$ Then, number of pencils $=108-x$

$\Rightarrow$ Cost of pens $=7x$

$\Rightarrow$ Cost of pencils $=3(108-x)$

According to the question,

$7x+3(108-x)=564$

$7x+324-3x=564$

$4x+324=564$

$4x=564-324$

$4x=240$

$\therefore$ $x=\frac{240}{4}=60$

$\Rightarrow$ Number of pencils $=108-60=48$

$\therefore$ The number of pens bought are $60$ and pencil bought are $48$.