BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Help with math problem!

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Sat Sep 19, 2009 6:17 pm

Help with math problem!

by zinc » Sat Sep 19, 2009 6:18 pm
Lina wrote a set of books called ______. Here is a picture of them lined up together on the library shelf, where the bookworm lives!
The pages of each book are 1in thick,
and both the front and back covers are 1/4 inch thick each,
Exactly how much distance does the bookworm travel if it eats through the first page of the last book
to the last page of the first book
there are six books
all like together; no space between them

A.7
B.7.5
C.8
D. 8.5
E. 9
Top
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 399
Joined: Wed Apr 15, 2009 3:48 am
Location: india
Thanked: 39 times

by xcusemeplz2009 » Mon Sep 21, 2009 3:58 am
IMO D
It does not matter how many times you get knocked down , but how many times you get up
Top
Junior | Next Rank: 30 Posts
Posts: 27
Joined: Thu Jul 23, 2009 6:29 am
Thanked: 3 times

by aa2kash » Mon Sep 21, 2009 4:58 am
AS per my understanding; the worm ate 4 books completly and the front cover of the last book + back cover of the first book.
each book is 1.5 inch thick.

4 books = 6 inch
front cover= .25 inch
last cover for the first book= .25 inch
I am getting a total of 6.5 inches.
which is none of the options. either i am misinterprating the question or something is missing in the question.
Would be great if somebody else will look into this.
thanks in advance.
Top
Senior | Next Rank: 100 Posts
Posts: 65
Joined: Thu Jul 02, 2009 10:38 pm
Location: Bangalore
Thanked: 1 times

by engg.manik » Mon Sep 21, 2009 7:01 am
The worm has not travelled all the pages and the back cover of the last book & the cover of the first book, which means he has not travelled one book in total.That means he has travelled 5 books in total.

Distance for one book = 1inch + 1/4 inch + 1/4 inch = 3/2 inch.

Distance for 5 books = 5*3/2 = 7.5 inches.

ANS is B.

What is the original ans
Top
Master | Next Rank: 500 Posts
Posts: 107
Joined: Tue Sep 15, 2009 7:18 pm
Location: Pune, India
Thanked: 6 times
GMAT Score:630

answering with a picture, well atleast a depiction :)

by vivekjaiswal » Mon Sep 21, 2009 8:00 pm
Guys,

I have tried to put down the question into a symbolic picture, as I understand it.

|--y||---||---||---||---||x--|

One book is pair of pipes(|) and its 1 inch thickness depicted by the dashes(-). The worm supposedly starts from 'x' and stops at 'y'.

Now if every | is 1/4 inches and every book is 1 inch, the worm travels a total of 10*1/4 = 2.5 inches + 4*1 = 6.5 inches.

Which unfortunately is not an option :(

Zinc,

Would request you yo clarify if our depiction is wrong, and tell us the correct answer to this one.


Cheers,
Vivek.
Top
Senior | Next Rank: 100 Posts
Posts: 64
Joined: Sat Aug 01, 2009 3:13 am
Thanked: 5 times
Followed by:1 members
GMAT Score:740

by mohitsharda » Mon Sep 21, 2009 8:22 pm
Consider the arrangement as follows:
|-||-||-||-||-||-|
the - represents 1 inch thick pages
the | represents cover (front or back... both have same thickness - .25 inch)

Total distance travelled = (6*1)+(5*.25)+(5*.25)
= 6+1.25+1.25 = 8.5 inches
6*1: for 1 inch thick pages.
5*.25: 5 front covers will be passed by the worm (2nd book to 6th book only).
5*.25: 5 back covers (1st book to 5th book only)

Answer D = 8.5
MS
Top
Master | Next Rank: 500 Posts
Posts: 107
Joined: Tue Sep 15, 2009 7:18 pm
Location: Pune, India
Thanked: 6 times
GMAT Score:630

by vivekjaiswal » Mon Sep 21, 2009 9:05 pm
mohitsharda wrote:Consider the arrangement as follows:
|-||-||-||-||-||-|
the - represents 1 inch thick pages
the | represents cover (front or back... both have same thickness - .25 inch)

Total distance travelled = (6*1)+(5*.25)+(5*.25)
= 6+1.25+1.25 = 8.5 inches
6*1: for 1 inch thick pages.
5*.25: 5 front covers will be passed by the worm (2nd book to 6th book only).
5*.25: 5 back covers (1st book to 5th book only)

Answer D = 8.5
Mohitsharda,

I hope you noticed the worm travels from the first page of the last book to the last page of the first book, which means it avoided travelling the 1 inch of the last book and the same of the first book. :)

Cheers,
Vivek
Top
Post new topic Post Reply
• Page 1 of 1