Question

the cost of some books is rupees 60. cost of every book is the same. if the bookseller decrease the cost of the book by rupees 1 ,one gets 5 books more for the same amount. what is the cost of each book and how many books are purchased?

Answer 1

Answer:

Original rice = rs 4 , books bought = 15

Reduced Price = Rs 3  , books bought = 20

Step-by-step explanation:

Let say cost of one book = x rs

number of books bought in rs 60  = 60/x

Reduced cost = x-1 rs

Book bought in 60 rs at reduced price = 60/(x-1)

As 5 books bought extra

60/(x-1) = 60/x + 5

60x = 60(x-1) + 5x(x-1)

12x = 12(x-1) + x(x-1)

12x = 12x - 12 + x^2 - x

x^2 - x - 12 = 0

x^2 - 4x + 3x - 12 = 0

x(x-4)+3(x-4) = 0

(x+3)(x-4)=0

x = 4    as Price can not be negative

Price of book = Rs 4

Reduced price = 4-1 = Rs 3

Books bought earlier = 60/4 = 15

Book bough with reduced price = 60/(4-1) = 20