Question

if the price of a book is reduced by rupees 5 a person can buy 5 4 books for rupees 330 price of the book​

Answer 1

The original price is 20 Rs

Step-by-step explanation:

Let's say the price of one book =  y

Let the no. of books purchased = x

Total cost = xy

But we are given the total cost = 300

xy = 300

Now according to the statement of the question a book is reduced by 5 Rs therefore a person can buy 5 more books.

Now the price of one book = y-5

The total no. of books purchased = x+5

Total cost = (x +5) (x-5)

300 = xy - 5x + 5y - 25

300 = 300 - 5x + 5y - 25

- 5x + 5y - 25 = 0

- 5x + 5y = 25

-x +y = 5

- 300 / y + y = 5

- 300 +y^2 / y = 5

y^2 - 5y - 300 =0

y^2 - 20y + 15y  - 300 =0

y(y - 20)  + 15 (y - 20) = 0

(y - 20) (y +15) = 0

y = 20 and y = -15

Y ≠ -15

Therefore the original price is 20 Rs

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