
By: geethavasavi (offline) Saturday, March 05 2016 @ 11:35 PM CST (Read 1370 times)



geethavasavi 
Hi ,
Please help to solve this problem
In a class library, there are some fiction and nonfiction books. If the monitor removes 1 nonfiction book from the library, 1/7 of the remaining books are nonfiction books. If the monitor had removed 2 fiction books instead, then 1/5 of the remaining books are nonfiction books. How many books are there in the class library?
ans : 17 books
Thanks & Regards,
Geetha

Newbie
Registered: 03/17/11 Posts: 10





By: echeewh (offline) Sunday, March 06 2016 @ 01:05 AM CST



echeewh 
Hey Geetha,
I think there is something wrong with the answer you provided. Appreciate that you recheck again. Thank you.
Using the answer of 17 books, let us go thru the question.
If there were 17 books and after 1 NF book removed, there were 16 books remaining. (1/7) of the remaining books were NF, and this results in (16/7) or (2 2/7) ???
If we continue with the question, I think you will find even more discrepancies.
Trust this reasonably explains why the answer of 17 does not really fit into the question.
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 627





By: geethavasavi (offline) Sunday, March 06 2016 @ 01:55 AM CST



geethavasavi 
Hi edward,
the answer may be wrong. But the how to approach this kind of sum, As my kid received similar question in her exam
Thanks & REgard,s
Geeth

Newbie
Registered: 03/17/11 Posts: 10





By: echeewh (offline) Sunday, March 06 2016 @ 02:06 AM CST



echeewh 
Hey <Geetha>,
Following is my worked solution :
<If 1 NF book removed>
NF : F
1 : 6
<Before>
NF = 1u + 1
F = 6u
<If 2 F books removed>
NF = 1u + 1
F = 6u  2
Remaining books = 1u + 1 + 6u  2 = 7u  1
Given that 1/5 of remaining are NF books, we have ...
(1/5) × (7u  1) = 1u + 1
7u  1 = 5 × (1u + 1)
7u  1 > 5u + 5
7u  5u > 5 + 1
2u > 6
1u > 3
Total books in library = <Before> NF + F
= 1u + 1 + 6u = 7u + 1
> (7 × 3) + 1 = 21 + 1 = 22
======
Trust this helps.
Do let me know again if there's further clarification.
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 627



