Question

Cost of 2 pens and 5 pencils is ₹ 25 , also cost of 2pens and 3 pencils is ₹19. Find the cost of3 pens and 4 pencils?​

Answer 1

Answer:

the answer is Rs.42

Step-by-step explanation:

cost of 1 pen = 10

cost of 1 pencil = 3

Answer 2

★ Given :-

• Cost of 2 pens and 5 pencils is ₹25.
• Cost of 2 pens and 3 pencils is ₹19.

★ To find :-

• Cost of 3 pens and 4 pencils = ?

★ Solution :-

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

According to the question,

• 2x + 5y = 25 ----- [Equation 1]
• 2x + 3y = 19 ------ [Equation 2]

We shall solve the question using elimination method.

Subtracting Equation 2 from Equation 1,

2x + 5y = 25

{-} 2x + 3y = 19

2y = 6

→ 2y = 6

→ y = 6 ÷ 2

→ y = 3

∴ The cost of 1 pencil is ₹3

Now, substitute the value of y in Equation 2 for finding the value of x.

2x + 3y = 19

→ 2x + 3(3) = 19

→ 2x + 9 = 19

→ 2x = 19 - 9

→ 2x = 10

→ 2x = 5

→ x = 5 ÷ 2

→ x = 2.5

∴ The cost of 1 pen is ₹2.5

For finding the value of 3 pens and 4 pencils ✏️:

3x + 4y

= 3(2.5) + 4(3)

= 7.5 + 12

= 19.5

∴ The cost of 3 pens and 4 pencils is ₹19.5