Question

sanvipurchase some books for rupees 120 if she purchased three more books for the same amount each book would have cost for the rupees2 less find the number of books purchase by sanvi and the price of each book is​

Answer 1

Answer:

The number of books purchased by Sanvi is 12 and the price of each book is Rs. 10.  

Step-by-step explanation:

Step 1:

It is given that Sanvi purchased some books for Rs. 120

Let the no. of books purchased by Sanvi be "x".

So,  

The cost of each book = Rs. [120/x] ...... (i)

Step 2:

Also given that she purchases 3 more books for the same price  

Now, the no. of books with Sanvi will be "(x+3)".

and,

The cost of each book will be = Rs. [120/(x+3)] ...... (ii)

Step 3:

According to the question and substituting the values from (i) & (ii), we get

⇒ 120 [(x+3-x)/x(x+3)] = 2

⇒ 60 [3/(x² + 3x)] = 1

⇒ 180 = x² + 3x

⇒ x² + 3x - 180 = 0

⇒ x² + 15x - 12x - 180 = 0

⇒ x(x+15) - 12(x+15) = 0

⇒ (x + 15)(x - 12) = 0

⇒ x = - 15 or 12

neglecting the negative value

⇒ x = 12 ← no. of books purchased by Sanvi

∴ The cost of each book = 120/x = 120/12 = Rs. 10

Answer 2

Sanvi purchased some x books

Let cost of each book be ₹y

Then total cost will be xy= 120