Last visit was: 24 Nov 2024, 14:16 It is currently 24 Nov 2024, 14:16

Close

GRE Prep 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
Your Progress

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

Practice
Pays

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Verbal Expert
Joined: 18 Apr 2015
Posts: 30017
Own Kudos [?]: 36379 [31]
Given Kudos: 25928
Send PM
Most Helpful Expert Reply
avatar
Supreme Moderator
Joined: 01 Nov 2017
Posts: 371
Own Kudos [?]: 470 [5]
Given Kudos: 0
Send PM
Most Helpful Community Reply
avatar
Intern
Intern
Joined: 15 Sep 2018
Posts: 41
Own Kudos [?]: 31 [15]
Given Kudos: 0
GRE 1: Q166 V158
Send PM
General Discussion
avatar
Manager
Manager
Joined: 23 Oct 2018
Posts: 57
Own Kudos [?]: 0 [0]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
Can you provide with explanation to this problem?
User avatar
Manager
Manager
Joined: 01 Nov 2018
Posts: 87
Own Kudos [?]: 144 [2]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
2
Expert Reply
jarabhuiyan wrote:
16. The given equation is l
m+ n
= m
n + l
= n
l + m
= k . Forming the three equations yields l = (m + n)k, m =
(n + l)k, n = (l + m)k. Summing these three equations yields
l + m + n = (m + n)k + (n + l)k + (l + m)k
= k[(m + n) + (n + l) + (l + m)]
= k(m + n + n + l + l + m)
= k(2m + 2n + 2l)
= 2k(m + n + l)
1 = 2k by canceling m + n + l from each side
1/2 = k
Hence, Column A equals 1/2. Since 1/2 is greater than 1/3, Column A is greater than Column B, and the
answer is (A).


You, are incredible!! Thanks!! This opened up my eyes to a whole new way of problem solving!!!
avatar
Intern
Intern
Joined: 04 Nov 2018
Posts: 44
Own Kudos [?]: 22 [0]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
jarabhuiyan wrote:
16. The given equation is l
m+ n
= m
n + l
= n
l + m
= k . Forming the three equations yields l = (m + n)k, m =
(n + l)k, n = (l + m)k. Summing these three equations yields
l + m + n = (m + n)k + (n + l)k + (l + m)k
= k[(m + n) + (n + l) + (l + m)]
= k(m + n + n + l + l + m)
= k(2m + 2n + 2l)
= 2k(m + n + l)
1 = 2k by canceling m + n + l from each side
1/2 = k
Hence, Column A equals 1/2. Since 1/2 is greater than 1/3, Column A is greater than Column B, and the
answer is (A).


Thank you so much for this.
avatar
Intern
Intern
Joined: 21 Nov 2018
Posts: 21
Own Kudos [?]: 11 [0]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
I tried the following approach and got k = -1 , can someone explain where I went wrong.
l(n+l)=m(m+n) { cross multiplying the first 2 terms}
ln+lpow2 = mpow2 +mn
n(l-m)= (m+l)*(m-l)
n= -(m+l)

Substituting this value in the last equation, yields k=-1 , and hence B>A
@chetan2u
avatar
Supreme Moderator
Joined: 01 Nov 2017
Posts: 371
Own Kudos [?]: 470 [2]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
2
Expert Reply
kunalkmr62 wrote:
I tried the following approach and got k = -1 , can someone explain where I went wrong.
l(n+l)=m(m+n) { cross multiplying the first 2 terms}
ln+lpow2 = mpow2 +mn
n(l-m)= (m+l)*(m-l)
n= -(m+l)

Substituting this value in the last equation, yields k=-1 , and hence B>A
@chetan2u



You cannot cancel out l-m from both sides..
n(l-m)= (m+l)*(m-l).....
n(l-m)-(m+l)(m-l)=0
n(l-m)+(m+l)(l-m)=0
(l-m)(n+m+l)=0
So either l=m or n=-(m+l)
Now you do not know which one is correct.
If l=m, then also (l-m)(n+m+l)=0 and then n+m+l is not necessarily equal to 0
Intern
Intern
Joined: 15 Jul 2021
Posts: 11
Own Kudos [?]: 20 [1]
Given Kudos: 17
Location: India
Concentration: Statistics, Technology
GPA: 3.78
WE:Design (Manufacturing)
Send PM
Re: l/m+n=m/n+l [#permalink]
1
As nothing is mentioned about l,m,n , they can be fraction or integer or any real number which satisfies the equation
\(\frac{l}{m+n}=\frac{m}{n+l}=\frac{n}{l+m}\)

The above equation is satisfied only when l=m=n

Hence the least value either \(\frac{l}{m+n}\) or \(\frac{m}{n+l}\) or \(\frac{n}{l+m}\) can take is \(\frac{1}{2}\)

So Quantity A = \(\frac{1}{2}\) and Quantity B is \(\frac{1}{3}\)

Therefore the answer is Quantity A is greater
avatar
Intern
Intern
Joined: 06 Jan 2022
Posts: 6
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
What about l = -4 and m = n = 2?

l / (m + n) = -4 / 4 = -1
m / (n + l) = 2 / (2 - 4) = -1
n / (m + l) = 2 / (2 - 4) = -1

what about this case?
avatar
Intern
Intern
Joined: 06 Jan 2022
Posts: 6
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
santosh93 wrote:
As nothing is mentioned about l,m,n , they can be fraction or integer or any real number which satisfies the equation
\(\frac{l}{m+n}=\frac{m}{n+l}=\frac{n}{l+m}\)

The above equation is satisfied only when l=m=n

Therefore the answer is Quantity A is greater


What when l = -4 and m = n = 2?
Verbal Expert
Joined: 18 Apr 2015
Posts: 30017
Own Kudos [?]: 36379 [1]
Given Kudos: 25928
Send PM
Re: l/m+n=m/n+l [#permalink]
1
Expert Reply
here the substitution method does not work best because could lead to a conflict answers

The best is to boil down the equality and see if k is > or < 1/3

regards
Manager
Manager
Joined: 09 May 2022
Posts: 50
Own Kudos [?]: 21 [0]
Given Kudos: 12
Send PM
l/m+n=m/n+l [#permalink]
Very simple.

Just use Componendo, Dividendo property, and you'll come up with l=m=n.
Hence K which is = l/(m+n) gets equal to 1/2.

Hence A is greater.
Intern
Intern
Joined: 25 Jun 2024
Posts: 1
Own Kudos [?]: 4 [4]
Given Kudos: 0
Send PM
Re: l/m+n=m/n+l [#permalink]
4
All previous answers are wrong.

2 cases can be distinguished for the equation l + m + n = 2 * k * (l + m + n)

1) If l + m + n is not zero, then k = 1 /2 as indicated by previous answers.

2) If it is zero, k = -1, as shown by the values l = 2, m = -1, n = -1

Therefore, the correct answer is D.
avatar
Intern
Intern
Joined: 29 Jul 2024
Posts: 1
Own Kudos [?]: 0 [0]
Given Kudos: 3
GRE 1: Q170 V150
Send PM
Re: l/m+n=m/n+l [#permalink]
nharakakos420 wrote:
All previous answers are wrong.

2 cases can be distinguished for the equation l + m + n = 2 * k * (l + m + n)

1) If l + m + n is not zero, then k = 1 /2 as indicated by previous answers.

2) If it is zero, k = -1, as shown by the values l = 2, m = -1, n = -1

Therefore, the correct answer is D.


Exactly, all the above answers are wrong. Please think more than blindly substituting one possible solution
Prep Club for GRE Bot
Re: l/m+n=m/n+l [#permalink]
Moderators:
GRE Instructor
84 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne