Question

The cost of 4 pens and 8 pencils is 84. If one pen costs 12 more than the cost of one pencil, find the price
of one pen and one pencil separately.
​

Answer 1

Answer:

Let the cost of one pen be x and one pencil be y

4x + 8y = 84.......(1)

x = y + 12.......(2)

Substituting the value of x in (1),

4(y+12) + 8y = 84

4y + 48 + 8y = 84

12y = 84 - 48

12y = 36

y = 36/12

y = 3

x = y + 12 = 3 + 12 = 15

Cost of one pen = x = 15

Cost of one pencil = y = 3

#WMK

Answer 2

$\huge\sf\pink{Answer}$

☞ Cost of pen = Rs 15

☞ Cost of pencil = Rs 3

$\rule{110}1$

$\huge\sf\blue{Given}$

✭ Cost of 4 pens and 8 pencil = 84

✭ Cost of 1 pen is 12 more than the cost of 1 pencil

$\rule{110}1$

$\huge\sf\gray{To \:Find}$

➢ Cost of pen and pencil?

$\rule{110}1$

$\huge\sf\purple{Steps}$

◕ Let the cost of one pen be ₹x and cost of a pencil be ₹y.

As per the the question ;

❍ The cost of 4 pens and 8 pencils is ₹84.

$\sf 4x + 8y = 84 \quad ... (i)$

❍ One pen cost ₹12 more than the cost of a pencil.

$\sf x = 12 + y \quad ... (ii)$

Substituting the value of (ii), in (i) -

➳ 4x + 8y = 84

➳ 4(12 + y) + 8y = 84

➳ 48 + 4y + 8y = 84

➳ 48 + 12y = 84

➳ 12y = 84 - 48

➳ 12y = 36

➳ $\sf y = \dfrac{36}{12}$

➳ $\sf\orange{ y = 3}$

Putting the value of y in (ii),

$\leadsto\sf x = 12 + y$

$\leadsto\sf x = 12 + 3$

$\leadsto\sf\orange{ x = 15}$

$\rule{170}3$