Question

(please answer to the question )
9 pens and 5 pencils cost 154, and 13 pens and 7 pencils cost 222. What is the cost of one pen and one pencil separately? explain ( ans=pen 16 , pencil= 2)​

Answer 1

Step-by-step explanation:

Given -

• 9 pens and 5 pencils cost Rs. 154
• 13 pens and 7 pencils cost Rs 222

To Find -

• What is the cost of one pen and one pencil separately

Let x be the cost of pens

And

y be the cost of pencils

According to the question :-

• 9 pens and 5 pencils cost Rs 154

It means,

• 9x + 5y = 154 ...... (i)

And

• 13 pens and 7 pencil cost Rs 222

It means,

• 13x + 7y = 222 ....... (ii)

Now, From (i) and (ii), we get :

[ 9x + 5y = 154 ] × 7

[ 13x + 7y = 222 ] × 5

→ 63x + 35y = 1078

65x + 35y = 1110

(-) (-) (-)

_______________

→ -2x = -32

→ x = -32/-2

→ x = 16

Now, Substituting the value of x on (i), we get :

→ 9x + 5y = 154

→ 9(16) + 5y = 154

→ 144 + 5y = 154

→ 5y = 10

→ y = 10/5

→ y = 2

Hence,

The cost of pencil is Rs 2

And

The cost of pen is Rs 16

Answer 2

$\large{\boxed{\underline{\underline{\bf{\red{Answer:-}}}}}}$

$\large\underline\mathrm{The \: cost \: of \: pen \: is \: Rs. \: 16}$

$\large\underline\mathrm{The \: cost \: of \: pencil \: is \: Rs. \: 2}$

$\large\underline\mathrm{Given:-}$

• 9 pens and 5 pencils cost Rs. 154.
• 13 pens and 7 pencils cost Rs. 222.

$\large\underline\mathrm{To \: find}$

• the cost of one pen and one pencil .

$\large\underline\mathrm{Solution}$

• Let the cost of pens is x and the cost of pencils is y

$\large\underline\mathrm{Now,}$

$\implies$ 9x + 5y = 154. ...(1)

$\implies$ 13x + 7y = 222. (2)

$\large\underline\mathrm{From \: the \: eq. \: (1) \: × \: 7 \: and \: eq. \: (2) \: × \: 5. \: we \: get,}$

$\implies$ [9x + 5y = 154] × 7

$\implies$ [13x + 7y = 222] × 5

$\implies$ 63x + 35y = 1078

$\implies$ 65x + 5y = 1110

$\implies$ -2x = -32

$\implies$ x = -32/-2

$\implies$ x = 16

$\large\underline\mathrm{Now,}$

$\large\underline\mathrm{put \: the \: value \: of \: x \: in \: eq. \: (1).}$

$\implies$ 9x + 5y = 154

$\implies$ 9(16) + 5y = 154

$\implies$ 144 + 5y = 154

$\implies$ 5y = 154 - 144

$\implies$ 5y = 10

$\implies$ y = 10/5

$\implies$ y= 2

$\large\underline\mathrm{hence,}$

$\large\underline\mathrm{The \: cost \: of \: pen \: is \: Rs. \: 16}$

$\large\underline\mathrm{The \: cost \: of \: pencil \: is \: Rs. \: 2}$

$\large\underline\mathrm{Hope \: it \: helps \: you \: plz \: mark \: me \: brainlist}$