Question

On noticing the shortage in supply of books, a bookseller increases Rs.10 more on the selling price of the book.If the bookseller had not changed the price, the person could buy more 10 books for Rs.3000. Find the original selling price of the book.By changing the selling price of the book, the bookseller violates which value of life?

Answer 1

Original selling price of the book = Rs x
Increased selling price = Rs 10 + x
Total amount spent = Rs 3000
No. of books can be bought with original seling price = 3000/x
No. of books can be bought with increased price = 300/(10+x)
As per the question, 

$\frac{3000}{x} = \frac{3000}{x} + 10$

$\frac{3000}{x} = \frac{3000+100+10x}{10+x}$
On crossmultiplication and simplification 

x²+10x - 3000 = 0

(x+60(x-50) = 0

x = 50

The original selling price = Rs 50

Answer 2

1.
1. Original selling price of  book = Rs x
2. Increased selling price = Rs 10 + x
Total amount spent = Rs 3000
Number of books can be bought with original seling price = 3000/x
Number of books can be bought with increased price = 300/(10+x)
According to above asked question,

by crossmultiplication we get,

x²+10x - 3000 = 0

(x+60(x-50) = 0

x = 50

The original selling price = Rs 50