Question

Mohit bought some pens and pencils from rs 564 if each pens cost rs 7 and each pencil cost rs 3 and the total number of pens and pencils watch 108 find the number of pens and pencils

Answer 1

$\underline{\textbf{Question}}$

Mohit bought some pens and pencils from rs 564 if each pens cost rs 7 and each pencil cost rs 3 and the total number of pens and pencils was 108 find the number of pens and pencils

$\underline{\textbf{Answer}}$

Let Total Pen=x

Total Pencil=y

Total Pen and Pencil=108

MEANS

x+y=108

x=108-y. (Equation 1)

Each Pen Cost=₹7

Total Pen Cost=7×x=₹7x

Each Pencil Cost=₹3

Total Pencil Cost=3×x=₹3x

Total Cost=₹564

MEANS

7x+3y=564

7(108-y)+3y=564. (x=108-y)

756-7y+3y=564

-7y+3y=564-756

-4y=-192

$y= \frac{ - 192}{ - 4} \: \: ( - \: - = + ) \\ \\ y=48$

We got=y=48

Total Pencil=48

Then Pen=108-48=60

Total Pen=60

$\boxed{\textbf{Check}}$

60×7+48×3

420+144

=564

$\boxed{\mathbf{Pencil=48}}$

$\boxed{\mathbf{Pen=60}}$