A one meter long wire is to be marked for cutting at interva

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 107
Joined: Tue Oct 07, 2014 3:50 am
Image

Hi All,

Could anyone please take a look at this question and share the analyses..?

Thanks much!!

Best,
Mallika

User avatar
Legendary Member
Posts: 2663
Joined: Wed Jan 14, 2015 8:25 am
Location: Boston, MA
Thanked: 1153 times
Followed by:128 members
GMAT Score:770

by DavidG@VeritasPrep » Tue Feb 10, 2015 6:20 am
First imagine a line with the following cuts:

---1/5---1/3----2/5----3/5----2/3-----4/5-----

Easiest way to find the lengths of those pieces is to find a common denominator. In this case, 15 will do. So let's redraw above like so:

---3/15---5/15----6/15----9/15----10/15-----12/15-----

Longest piece is the one from 6/15 to 9/15. 9/15 - 6/15 = 3/15 = 1/5. Answer is C.
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save $100 off any live Veritas Prep GMAT Course

User avatar
Legendary Member
Posts: 2131
Joined: Mon Feb 03, 2014 9:26 am
Location: https://martymurraycoaching.com/
Thanked: 955 times
Followed by:140 members
GMAT Score:800

by MartyMurray » Tue Feb 10, 2015 6:41 am
A one meter long wire is to be marked for cutting at intervals of fifths and thirds. How long is the largest segment of the wire if the wire is cut at the marked intervals? (Source: BellCurves)

A) 1/15

B) 2/15

C) 1/5

D) 4/15

E) 9/15

There is a quick way to do this if you see a couple of things.

The first thing you need to see is that the longest you can have is a 1/5 length, because the wire is getting cut into fifths. So all the answers greater than 1/5 are out. Eliminate D and E.

Now the question is is there ever an entire 1/5.

The next thing you need to see is that 1/5 < 1/3. So the first cut will be at 1/5 and the first 1/3 cut will be past that. So there will be at least one 1/5 length.

So 1/5 is the answer and the problem is done.

Choose C.
Marty Murray
Perfect Scoring Tutor With Over a Decade of Experience
MartyMurrayCoaching.com
Contact me at [email protected] for a free consultation.

User avatar
Legendary Member
Posts: 2663
Joined: Wed Jan 14, 2015 8:25 am
Location: Boston, MA
Thanked: 1153 times
Followed by:128 members
GMAT Score:770

by DavidG@VeritasPrep » Tue Feb 10, 2015 7:03 am
Note that this question is virtually identical to #226 from the OG:

A straight pipe 1 yard in length was marked off in
fourths and also in thirds. If the pipe was then cut into
separate pieces at each of these markings, which of
the following gives all the different lengths of the
pieces, in fractions of a yard?

(A)1/6 and 1/4 only

(B)1/4 and 1/3 only

(C)1/6 ,1/4 and 1/3

(D)1/12 ,1/6, and 1/4

(E)1/12,1/6, and 1/3

OA D
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save $100 off any live Veritas Prep GMAT Course

User avatar
Legendary Member
Posts: 2131
Joined: Mon Feb 03, 2014 9:26 am
Location: https://martymurraycoaching.com/
Thanked: 955 times
Followed by:140 members
GMAT Score:800

by MartyMurray » Tue Feb 10, 2015 7:26 am
DavidG@VeritasPrep wrote:Note that this question is virtually identical to #226 from the OG:

A straight pipe 1 yard in length was marked off in
fourths and also in thirds. If the pipe was then cut into
separate pieces at each of these markings, which of
the following gives all the different lengths of the
pieces, in fractions of a yard?

(A)1/6 and 1/4 only

(B)1/4 and 1/3 only

(C)1/6 ,1/4 and 1/3

(D)1/12 ,1/6, and 1/4

(E)1/12,1/6, and 1/3
This one can be done in a way similar to the quick way that works for the other one.

1/4 is less than 1/3. So 1/4 works and anything greater, such as 1/3, does not. Eliminate B, C and E.

A and D remain.

1/4 = 3/12 1/3 = 4/12. So they are 1/12 apart.

A does not include 1/12. So A is out.

Only choice left is D. Click it, and on to the next question.
Marty Murray
Perfect Scoring Tutor With Over a Decade of Experience
MartyMurrayCoaching.com
Contact me at [email protected] for a free consultation.

Master | Next Rank: 500 Posts
Posts: 107
Joined: Tue Oct 07, 2014 3:50 am

by mallika hunsur » Thu Feb 12, 2015 5:02 am
Wow! That really helps!
Thanks so much Marty and David!!