GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 14 Dec 2019, 06:04

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Susan marks-off a 2-meter cloth into multiples of three and five. She

Author Message
TAGS:

Hide Tags

Manager
Joined: 31 Oct 2018
Posts: 77
Location: India
Susan marks-off a 2-meter cloth into multiples of three and five. She  [#permalink]

Show Tags

18 Apr 2019, 10:00
1
5
00:00

Difficulty:

85% (hard)

Question Stats:

39% (02:41) correct 61% (02:24) wrong based on 57 sessions

HideShow timer Statistics

Susan marks-off a 2-meter cloth into multiples of three and five. She then breaks the cloth along all the markings and removes one piece of every distinct length. What fraction of the original cloth remains?

A. 2/5
B. 7/15
C. 1/2
D. 8/15
E. 3/5
Math Expert
Joined: 02 Aug 2009
Posts: 8320
Re: Susan marks-off a 2-meter cloth into multiples of three and five. She  [#permalink]

Show Tags

18 Apr 2019, 20:14
btrg wrote:
Susan marks-off a 2-meter cloth into multiples of three and five. She then breaks the cloth along all the markings and removes one piece of every distinct length. What fraction of the original cloth remains?

A. 2/5
B. 7/15
C. 1/2
D. 8/15
E. 3/5

Of course, the question is wrongly worded. How can we cut a 2 units thing into MULTIPLES of 3 and 5.
So, it is meant to be cut into thirds and fifths..

So basically we are cutting at 1/3 and 1/5 of 2..
Different locations of cut...
0, 2/5, 2/3, 4/5, 6/5, 4/3, 8/5, 1...
Distinct lengths...(2/5-0 or 2/5), (2/3-2/5 or 4/15), (4/5-2/3 or 2/15).. Rest all will again be 2/5, 2/15, 4/15

Sum of these lengths = 2/5+4/15+2/15=4/5...
Left is 2-4/5=6/5...
6/5 as a fraction of 2 is (6/5)/2=6/(5*2)=3/5..

E
_________________
Manager
Joined: 17 Sep 2017
Posts: 100
Re: Susan marks-off a 2-meter cloth into multiples of three and five. She  [#permalink]

Show Tags

26 Apr 2019, 23:13
hi, can anyone offer an explanation for the answer?
Manager
Joined: 31 Oct 2018
Posts: 77
Location: India
Re: Susan marks-off a 2-meter cloth into multiples of three and five. She  [#permalink]

Show Tags

26 Apr 2019, 23:23
abhishek31 wrote:
hi, can anyone offer an explanation for the answer?

Hey abhishek31, sorry to say this but there is no official explanation for this question. Please refer to prev post by chetan2u
Intern
Joined: 27 Apr 2019
Posts: 7
Re: Susan marks-off a 2-meter cloth into multiples of three and five. She  [#permalink]

Show Tags

27 Apr 2019, 21:22
The actual length is irrelevant, so pretend length = 1 for simplicity, and draw a line segment from 0-1.

Mark a tick at all the appropriate spots (1/3, 2/3) and (1/5, 2/5, 3/5, 4/5). You should see there are 3 distinct lengths that are formed by these cuts:

A = 1/5
B = 1/3 - 1/5 = 2/15
C = 2/5 - 1/3 = 1/15

*be careful and note that the middle section is simply a type A length (1/5).

Take the sum of A,B,C and subtract it from 1 (i.e. 100%) to get the answer.

Conversely, it is probably easier to just see it on the number line with A,B,C segments being next to each other and terminating at 2/5. (1-2/5 = 3/5)
Re: Susan marks-off a 2-meter cloth into multiples of three and five. She   [#permalink] 27 Apr 2019, 21:22
Display posts from previous: Sort by