Question

A pen and a book currently have the same price. If the price or a pen rises by 5% and the price of a book goes up by 3% how much more will it cost to buy 3 pens and books ? (a)3%
(b) 4%
(c) 5%
(d) 8%​

Answer 1

The total cost of 8 books and 5 pens is 420 rupees and the total cost of 5 books and 8 pens is 321 rupees. Find the cost of 1 book and 2 pens.

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

solution

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