Question

The total cost of 3 books and 5 pens is 80 rupees and the total cost of 5 books and 8 pens is 110 rupees. Find the cost of the book and Pen

Answer 1

Answer:

Let cost of book be x & cost of pen be y

⇒8x+5y=420;⇒5x+8y=321

Adding = 13x+13y=741;x+y=57 ____ (1)

Subtracting = 3x−3y=99;x−y=33

substituting x=y+33 in equation (1) we get :

y+33+y=57⇒2y=24⇒y=12

so x=12+33=45

cost of 1 book & 2 pens = 45+2(12)= 45+24

=69Rs