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The cost of 4 pens and 4 pencil boxes is Rs 100. Three times the cost of a pen is Rs 15 more than the cost of a pencil box. Form the pair of linear equations for the above situation. Find the cost of a pen and a pencil box

Solution:

Consider the cost of a pen as ₹x.

Consider the cost of a pencil box as ₹y.

According to the given condition,

4x + 4y = 100

x + y = 25-------(1)

3x = y + 15

3x - y = 15-------(2)

(1) and (2) are the pair of linear equations in two variables.

Add (1) and (2),we get,

4x = 40

x = 10.

Substituting x = 10 in (1),we get.

y = 25 - 10

y = 15.

Therefore, the cost of a pen and a pencil box are ₹10 and ₹15, respectively.

✦ Try This: The cost of 5 pens and 5 pencil boxes is Rs 200. Three times the cost of a pen is Rs 20 more than the cost of a pencil box. Form the pair of linear equations for the above situation. Find the cost of a pen and a pencil box

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 3

NCERT Exemplar Class 10 Maths Exercise 3.4 Problem 4

The cost of 4 pens and 4 pencil boxes is Rs 100. Three times the cost of a pen is Rs 15 more than the cost of a pencil box. Form the pair of linear equations for the above situation. Find the cost of a pen and a pencil box

Summary:

The cost of 4 pens and 4 pencil boxes is Rs 100. Three times the cost of a pen is Rs 15 more than the cost of a pencil box. The cost of a pen and a pencil box are ₹10 and ₹15, respectively.

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