Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains?
A. 2/5
B. 7/15
C. 1/2
D. 8/15
E. 3/5
The OA is E.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
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Kim finds a 1-meter tree branch and marks it off in...
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Jay@ManhattanReview
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Pl. see the image below to get this better. The 1-meter tree branch is shown as a piece of 15 parts as the LCM of 1/3 and 1/5 is 1/15.swerve wrote:Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains?
A. 2/5
B. 7/15
C. 1/2
D. 8/15
E. 3/5
The OA is E.
Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
The part of the branch after its 2/5th part is unwanted as the further cuts do not provide distinct lengths.
The fraction of the original branch remains = 1 - 2/5 = 3/5.
The correct answer: E
Hope this helps!
-Jay
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GMATGuruNY
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Ignore the given length of 1-meter. The problem can be solved using any length.swerve wrote:Kim finds a 1-meter tree branch and marks it off in thirds and fifths. She then breaks the branch along all the markings and removes one piece of every distinct length. What fraction of the original branch remains?
A. 2/5
B. 7/15
C. 1/2
D. 8/15
E. 3/5
Let length = 15 meters.
Dividing 15 into 3rds will yield markings at 5 and 10.
Dividing 15 into 5ths will yield markings at 3, 6, 9, and 12.
Listing the markings in order:
0......3....5..6......9..10....12......15
There are only 3 distinct lengths: 1 meter, 2 meters, and 3 meters.
Subtracting these 3 distinct lengths from 15, we get:
Length remaining = 15-1-2-3 = 9.
Remaining length/Total length = 9/15 = 3/5.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
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