Question

answer is 45 and those who will give step by step solution will get brain list.

Answer 1

let cost of 1 book purchased is Rs X

number of books purchased for Rs 720 will be = 720/x
as per given conditions if cost of one book is reduced by RS 5 each than new cost of 1 book will be = Rs (X-5)
number of books will be =720/(x-5)

if cost reduced RS 5 for each books than 2 books will purchased more 720/(x-5)-720/x=2



After that refer to the attachment


:)