please answer the above question.....
Answers
Answer:
4,15
Step-by-step explanation:
Let the cost of each book be 'x' and number of books purchased be 'y'.
We have,
Cost of some books is 60.
=> xy = 60.
∴ y = (60/x)
(i)
Given that bookseller decreases the cost by 1 => (x - 1).
Given that one gets 5 more books for same amount => (5 + y).
According to the given condition,
⇒ (x - 1)(5 + y) = 60
⇒ 5x + xy - 5 - y = 60
⇒ 5x + 60 - 5 - (60/x) = 60
⇒ 5x - 5 - (60/x) = 0
⇒ 5x² - 5x - 60 = 0
⇒ x² - x - 12 = 0
⇒ x² - 4x + 3x - 12 = 0
⇒ x(x - 4) + 3(x - 4) = 0
⇒ (x + 3)(x - 4) = 0
⇒ x = 4, -3{It cannot be negative}
⇒ x = 4.
When x = 4:
y = (60/4)
= 15.
Therefore:
Cost of each book is 4.
15 books are purchased.
Hope it helps!
Let the cost of book be Rs x.
So, the number of books that can be purchased= 60/x
When the cost of book is decreased by Rs 1,
The number of books that can be purchased would be 60/(x-1)
Now, according to the question
60/(x-1)= 60/x + 5
Multiplying by x(x-1) both sides,
60/(x-1)*x(x-1)=60/x*x(x-1) + 5*x(x-1)
60x= 60*(x-1) + 5x(x-1)
Using the distributive property of multiplication over addition, we get:
60x= 60x-60+5x^2-5x
Rearranging the above equation, we see that
5x^2-5x-60=0 or
x^2-x-12=0
Factorising the above quadratic equation,
(x+3)(x-4)=0
So,
x= -3 & x= 4
x= -3 is not possible, as cost can not be negative.
So, the cost of each book would be Rs 4.
The number of books that can be purchased= 60/4= 15