Saved Bookmarks
| 1. |
(1) The cost of some books is60. Cost of every book is the same. If the booksellerdecreases the cost of the book by ? 1, one gets 5 books more for the same amount.What is the cost of each book and how many books are purchased? |
|
Answer» Let the number of books = nTotal cost of books = 60 Then,Cost of each book = 60/n If price of each book decreased by Rs 1Then, Number of books = n + 5 Cost of each book will be = 60/(n + 5) Thus,60/(n+5) = 60/n - 160(1/n - 1/n+5) = 160(5) = n(n + 5)n^2 + 5n - 300 = 0n^2 + 20n - 15n - 300 = 0n(n + 20) - 15(n + 20) = 0(n - 15)(n + 20) = 0n = 15, - 20 As negative value not possible Therefore,Total number of books = 15Cost of each book = 60/15= 4 Rs |
|