Question

The price of 5 notebooks and 4 pens is 190 rupees. The price of 10 notebooks and 7 pens is 370 rupees. what is the price of a notebook. what is the price of a pen​

Answer 1

Step-by-step explanation:

Let the cost of a notebook be x

And the cost of a pen be y

Case 1:-

5 notebooks + 4 pens = Rs.190

➝ 5x + 4y = 190......(i)

Case 2:-

10 notebooks + 7 pens = Rs.370

➝ 10x + 7y = 370

Multiplying equation (i) with 2

➝ 2(5x + 4y = 190)

➝ 10x + 8y = 380.....(iii)

Equation (iii) - (ii)

➝ 10x + 8y - (10x + 7y) = 380 - 370

➝ 10x + 8y - 10x - 7y = 10

➝ y = 10

Substituting y = 10 in equation (i)

➝ 5x + 4y = 190

➝ 5x + 4(10) = 190

➝ 5x = 190 - 40

➝ 5x = 150

➝ x = $\dfrac{150}{5} = 30$

We have:-

• x = 30

• y = 10

Therefore:-

Cost of a notebook = Rs. 30

Cost of a pen = Rs. 10