Question

Mr A and Mr B went to a book store and purchased some note books and pens. Mr A gave Rs 120 for 5 note books and 2 pens while Mr B gave Rs 170 for 7 note books and 3 pens.If the cost of a pen is Rs x and cost of a pen is Rs y, then choose the correct option for the following questions.a)What is the linear equation for Mr A’s transition is book store.

Answer 1

Answer:

Cost of pen is 10 and

Cost of note book is 20

Answer 2

Question Understanding:-

Here,

Two person Mr A and Mr B went to a book store and purchase some note books and pens. Mr A gave Rs120 for 5 note books and 2 pens while Mr B gave rs170 for 7 note books and 3 pens . The cost of a notebook is Rs x and cost of a pen is y.

To Find :-

a) What is the linear equation for Mr A's transition?

b) What is the linear equation for Mr B'Day transition ?

c) Find the value of x and y ?

Solution :-

a) According to the question,

Mr A purchased 5 note books and 2 pens for Rs120

Therefore,

Linear equation for Mr A's transition

5x + 2y = 120

B) According to the question,

Mr B purchased 7 notebooks and 3 pens for Rs170

Therefore,

Linear equations for Mr B's transition

7x + 3y = 170

c) Now,

We have to find the cost of notebook that is x and cost of pen that is y

According to the question

Mr A purchased 5 note books and 2 pens for Rs120 and Mr B purchased 7 notebooks and 3 pens for Rs170

Therefore,

5x + 2y = 120.

5x = 120 - 2y

x = 120 - 2y / 5 ...eq( 1 )

7x + 3y = 170. ...eq( 2 )

Subsitute eq( 2 ) in eq( 1 ) we get :-

7( 120 - 2y/5 ) + 3y = 170

840 - 14y / 5 + 3y = 170

By taking LCM, we get :-

840 - 14y + 15y / 5 = 170

840 - 14y + 15y = 170 * 5

840 + y = 850

y = 850 - 840

y = 10

Subsitute the value of y in eq( 1 )

5x + 2( 10) = 120

5x + 20 = 120

5x = 120 - 20

5x = 100

x = 100/5

x = 20

Hence, The value of x and y is 20 and 10 $.$