Case study V: Deepak bought 3.notebooks and 2 pens for Rs 80. Latika bought the same types of notebooks and pens as

Questions

October 2023 2 3 Report

Case study V: Deepak bought 3.notebooks and 2 pens for Rs 80. Latika bought the same types of notebooks and pens as Deepak. He paid Rs 110 for 4 notebooks and 3 pens. 2
Form the pair of linear equations in two variables from this situation by taking cost of one notebook as Rs x and cost of one pen as Rs y.

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Answer:

Step-by-step explanation:

1) cost of Notebook = x

cost of Pen = y

As per Given information:

(i) 3 Notebooks + 2 pens = r s 80

3x + 24 = 80

similarly,

4 Notebooks + 3 pens = rs-110

4x + 34 = 110

3x + 2y = 80 and 4x + 3y = 110

2) cost of Notebook (x)

To find x

solve 3x + 2y = 80 -> (1)

4x + 3y = 110 -> (2)

by eliminating y

1 * 3

9x + 6y = 240

2 * 2

8x + 6y = 220

(-)(-) x = 20

therefore The cost of Notebook is rs. 20

(iii) Costs of pens (y)

To Find y eliminate x to substitute x = 20in 3x + 2y = 80(or) x = 20 in 3x + 2y = 80

4x + 3y = 110

3(20) + 2y = 80

60 + 2y = 80

2y = 80

y = 20/2

y = 10

The cost of pen = 10

(iv) 3 Notebooks (x = 15) and Pens (y = 12)

Find cost = ?

15x + 12y =

[x = 20][y = 10] = 15(20) + 12(10)

= 300 + 120

= Rs - 420

(v) Ram said that price of each notebook could be Rs-25.

Ajay felt that Rs-2.50 for one pen was too little. It should be at least Rs- 16 Deepak guess the cost of one pen is Rs-10 and Lohith guess the cost of one notebook is Rs-30

Therefore, estimation of Deepak is correct