Question

the price of 4 notebook and 7 pens is 115 rupees and the price of 4 notebooks and 2 pens is 90 ruppes what is the price of a notebook and what is the price of apen

Answer 1

Step-by-step explanation:

Given total cost of 5 pens and 10 pencil = Rs 30

5 pens + 10 pencils = 30

pens + 2 pencils = 1

also given pen cost 3 more than a pencil

i.e, pen = 3 + pencil.

pen - pencil = 3

pens + 2 pencils = 6

_______________

-3 pencils = -3

pencils = 1

pen - 1 = 3

pen = 4

cost of pencils = 1 cost of pen = 4

Answer 2

Given - Price of 4 notebook and 7 pens is 115 rupees

Price of 4 notebooks and 2 pens is 90 rupees

Find - Price of a notebook and a pen

Solution - Let x represent notebook and y represent pen.

As per the first statement,

4x + 7y = 115 : equation 1

As per the second statement,

4x + 2y = 90 : equation 2

Substracting equatiom 2 from 1.

4x + 7y = 115

- 4x + 2y = 90

We get, 5y = 25

y = 25/5

y = 5

So, price of a pen is Rs. 5

To find price of a notebook, keeping the value of pen in equation 1.

4x + 7*5 = 115

4x = 115 - 35

4x = 80

x = 20

So, Price of a notebook is Rs. 20

Hence, price of a notebook and a pen is Rs. 20 and Rs. 5 respectively.