Question

cost of 5 pens and 3 pencils is 65 Rupees the cost of 3 pens and 5 pencils is 55 rupees what is the price of pen and pencil ?

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Answer 1

Given :

• The cost of 5 pens and 3 pencils is 65 rupees.
• The cost of 3 pens and 5 pencils is 55 rupees.

To Find :

• Find the price of pen & pencil ?

Solution :

• Let us assume.

➣ The cost of one pen be x.

➣ And the cost of one pencil be y.

According to the question :

➣ 5x + 3y = 65 (i)

➣ 3x + 5y = 55 (ii)

Adding both the equation :

➣ 5x + 3y + 3x + 5y = 65 + 55

➣ 8x + 8y = 120

➣ 8(x + y) = 120

➣ (x + y) = 120/8

➣ x + y = 15

➣ x = 15 - y (ii)

In equation (ii).

• 3x + 5y = 55

Substituting the value of x.

➣ 3(15 - y) + 5y = 55

➣ 45 - 3y + 5y = 55

➣ 2y = 55 - 45

➣ 2y = 10

➣ y = 5

In equation (iii).

• x = 15 - y

Putting the value of y.

➣ x = 15 - 5

➣ x = 10

Hence,

• The cost of one pen = Rs. 10
• And the cost of one pencil = Rs. 5

Answer 2

A N S W E R :

• The cost of one pen = Rs. 10
• And the cost of one pencil = Rs. 5.