Question

Ravi buys no of books for Rs 60. If he
had bought 5 more books for same amount
each book would have cost him Rs I less
How many books did he buy? Find the
price of each book.​

Answer 1

Answer:

Ravi buys 15 books and price of each book is 4rs

Step-by-step explanation:

lets take number of books Ravi bought is x

Cost of each book is y= 60/x

If he had bought 5 more books for same amount each book would have cost him Rs 1 less, i,e

y-1 = 60/x+5

By solving these two equation

$y-1 =\frac{60}{x+5} \\\frac{60}{x}-1=\frac{60}{x+5}\\\frac{60-x}{x} =\frac{60}{x+5}\\60x+300-x^2-5x-60x=0\\x^2+5x-300= 0\\x^2+20x-15x-300=0\\x(x+20)-15(x+20)=0\\(x+20)(x-15)=0\\x=-20 or x= 15$

the value of x is 15. Hence ravis buys 15 books

Price of the each book is 60/15 = 4 rs