The answer is E.
Let the pieces of rope in the order of length are a,b,c(the longest).
We are given
c+b = 12
a+b = 11
we can derive c-a =1
Since we can't find a unique combination of values that satisfy the above equations, they cannot be solved.
Thank you Stuart and Ian. The posts are indeed useful.
@Stuart
Sometimes by plugging in values we can arrive at a unique solution, especially when a range in which values lie is given. Can we add this to the exception to the rule which Ian has given?
ds - value question
-
- Senior | Next Rank: 100 Posts
- Posts: 72
- Joined: Wed Oct 27, 2010 2:06 am
- Thanked: 2 times
- Followed by:1 members
-
- Master | Next Rank: 500 Posts
- Posts: 401
- Joined: Tue May 24, 2011 1:14 am
- Thanked: 37 times
- Followed by:5 members
-
- Master | Next Rank: 500 Posts
- Posts: 381
- Joined: Wed May 19, 2010 10:15 pm
- Thanked: 41 times
- Followed by:2 members
I would steer clear of all rules in equations. GMAT can be tricky as Ian rightly pointed out.
The best approach IMO is try your best to solve with the given information. First using either statements alone and then by combing both. Choose E if you fail to solve or get multiple answers.
The equations in this question are dangerously close to getting solved. Anything like integer values in the stem can give a valid solution.
An expansion of this problem could be what are the range of values for the three variables.
Answer a<b<c
5 < a < 5.5
6 < b < 5.5
6 < c
The best approach IMO is try your best to solve with the given information. First using either statements alone and then by combing both. Choose E if you fail to solve or get multiple answers.
The equations in this question are dangerously close to getting solved. Anything like integer values in the stem can give a valid solution.
An expansion of this problem could be what are the range of values for the three variables.
Answer a<b<c
5 < a < 5.5
6 < b < 5.5
6 < c
-
- Master | Next Rank: 500 Posts
- Posts: 160
- Joined: Tue Jul 07, 2009 1:09 pm
- Thanked: 1 times
- Followed by:1 members
- ronnie1985
- Legendary Member
- Posts: 626
- Joined: Fri Dec 23, 2011 2:50 am
- Location: Ahmedabad
- Thanked: 31 times
- Followed by:10 members
3 variables 2 equations, no solution=> (E) is answer
Follow your passion, Success as perceived by others shall follow you
yes u r ryt.The answer is E
prinit wrote:x+y+z =?
lets assume x is the shortest x<y<z
y+z=12 --eq 1
x+y=11 -- eq 2
------------
z-x=1
=>z=1+x
now put in 1
y=12-z=> 12-1-x
now put in 2
x+12-1-x=11 ...cant solve it for x...
so answer is E ..
-
- Senior | Next Rank: 100 Posts
- Posts: 97
- Joined: Sun Jun 24, 2012 11:23 pm
Long ones combined 12cgc wrote:If a rope is cut into three pieces of unequal length, what is the length of the shortest of these pieces of rope?
(1) The combined length of the longer two pieces of rope is 12 meters.
(2) The combined length of the shorter two pieces of rope is 11 meters.
for rope x + y + z = a
1. x + y = 12
2. y + z = 11
c. can you combine the two equations to create another separate equation? For example...
y = 12 -x
(12-x) + z = 11
Are these not distinct equations to satisfy the equation/variable rule?
Please help explain.
thanks,
Short one combined 11
so i 6 and 6 for long
and 5.1 and 5.9 for short one so 5.1 is the shortest
Option c
I am missing anything?
I got this question today with the BTG daily math emails, I'm not sure if I'm right but i would love her the experts thoughts on it.
If we can only 1 answer for the problem, then the statement or statements are Sufficient,
if We have a>b>c
from statement 1: a+b= 12 the rope isn't more than 18, L<18
from statement 2: b+c= 11 isn't shorter than 16, L>16.5
From both we know that the rope is 16.5<L<18 the difference is 1.5
and we also know that A-c =1, B is 0.5 between A and C,
if we pick numbers A=5.25
b:5.75
C:6.25
We satisfied that A+B=12
AND B+C=11
and total is 17.25 between the range 18-16.5
so I think the right answer is C unless we can find other solutions.
Regards
Kassim
If we can only 1 answer for the problem, then the statement or statements are Sufficient,
if We have a>b>c
from statement 1: a+b= 12 the rope isn't more than 18, L<18
from statement 2: b+c= 11 isn't shorter than 16, L>16.5
From both we know that the rope is 16.5<L<18 the difference is 1.5
and we also know that A-c =1, B is 0.5 between A and C,
if we pick numbers A=5.25
b:5.75
C:6.25
We satisfied that A+B=12
AND B+C=11
and total is 17.25 between the range 18-16.5
so I think the right answer is C unless we can find other solutions.
Regards
Kassim
- way2ashish
- Senior | Next Rank: 100 Posts
- Posts: 32
- Joined: Mon Sep 26, 2011 6:34 pm
If a rope is cut into three pieces of unequal length, what is the length of the shortest of these pieces of rope?
1. The combined length of the longer two pieces of rope is 12 meters.
2. The combined length of the shorter two pieces of rope is 11 meters.
AD BCE
A. Not Sufficient as it gives no info about the total length > X+Y = 12
D. Since is not sufficient hence D is ruled out.
B. Not sufficient as it gives no ifo about the total length > Y+Z = 11
C. Combining both we get > X-Z = 1 but still we have 2 variables but no other info
E. Which is the correct answer
1. The combined length of the longer two pieces of rope is 12 meters.
2. The combined length of the shorter two pieces of rope is 11 meters.
AD BCE
A. Not Sufficient as it gives no info about the total length > X+Y = 12
D. Since is not sufficient hence D is ruled out.
B. Not sufficient as it gives no ifo about the total length > Y+Z = 11
C. Combining both we get > X-Z = 1 but still we have 2 variables but no other info
E. Which is the correct answer
- way2ashish
- Senior | Next Rank: 100 Posts
- Posts: 32
- Joined: Mon Sep 26, 2011 6:34 pm
U r missing that all the three are of unequal sizes
Ganesh hatwar wrote:Long ones combined 12cgc wrote:If a rope is cut into three pieces of unequal length, what is the length of the shortest of these pieces of rope?
(1) The combined length of the longer two pieces of rope is 12 meters.
(2) The combined length of the shorter two pieces of rope is 11 meters.
for rope x + y + z = a
1. x + y = 12
2. y + z = 11
c. can you combine the two equations to create another separate equation? For example...
y = 12 -x
(12-x) + z = 11
Are these not distinct equations to satisfy the equation/variable rule?
Please help explain.
thanks,
Short one combined 11
so i 6 and 6 for long
and 5.1 and 5.9 for short one so 5.1 is the shortest
Option c
I am missing anything?