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

 It is currently 23 Oct 2019, 16:21

### 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

# When k, l, and m are different positive integers greater than 1, k+l+m

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 8033
GMAT 1: 760 Q51 V42
GPA: 3.82
When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

11 Jan 2016, 16:48
2
10
00:00

Difficulty:

45% (medium)

Question Stats:

57% (01:14) correct 43% (01:13) wrong based on 449 sessions

### HideShow timer Statistics

When k, l, and m are different positive integers greater than 1, k+l+m=?

1) km=15
2) kml=30

*A solution will be posted in two days.

_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Manager
Status: single
Joined: 19 Jan 2015
Posts: 84
Location: India
GPA: 3.2
WE: Sales (Pharmaceuticals and Biotech)
Re: When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

11 Jan 2016, 19:50
k, l and m are different positive integers greater than

from statement 1.
km=15,
possible solution are 3 and 5 or 5 and 3. we don't know value of l.

from statement 2

klm=30

possible values are 2,3 and 5.
all are possible different integers and greater than 1.

we can take any possible varibles as 2,3 and 5 or 3,2 and 5 . so sum equals=10.

so option B is correct.
Manager
Joined: 27 Jul 2014
Posts: 235
Schools: ISB '15
GMAT 1: 660 Q49 V30
GPA: 3.76
Re: When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

12 Jan 2016, 03:33
IMO E is correct
A. km =15
k can be 3 or 5 according to which m will be 5 or 3
insufficient

B, kml=30
k can be 2,3,5 according to which m nd l can also have multiple values

A+B
l =2
but again kor m can be anyone from 3 or 5

SO E
Intern
Joined: 05 Aug 2009
Posts: 2
Re: When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

12 Jan 2016, 20:02
k, l and m are different positive integers greater than 1.

from st.1:
km=15
which means --> km = 3*5 or 5*3 (order doesn't matter as finally they will add up)
But no information on l..
So, NOT SUFFICIENT.

from st.2:
kml=30
which means --> kml = 2*3*5 or 5*3*2 or any other way with 3 different positive integers (greater than 1) 2,3 and 5 (again, order doesn't matter as finally they will add up)
this is the only way in which 3 factors are available for kml=30
so k+m+l = 2+3+5 = 10
Hence, SUFFICIENT.

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 8033
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

13 Jan 2016, 18:58
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

When k, l, and m are different positive integers greater than 1, k+l+m=?
1) km=15
2) kml=30

In the original condition, there are 3 variables, which should match with the number of equations. So you need 3 equations. For 1) 1 equation, for 2) 1 equation, which is likely to make E the answer. When 1) & 2), k+l+m=10 si derived from (k,l,m)=(3,2,5),(5,2,3), which is unique and sufficient. Then the answer is C. Since this is an integer question which is one of the key questions, apply the mistake type 4(A).
In case of 1), you don’t know l, which is not unique and not sufficient.
In case of 2), in (k,l,m)=(2,3,5),(2,5,3),(3,2,5),(3,5,2),(5,2,3),(5,3,2), k+l+m=10 is derived, which is unique and sufficient. Therefore, the answer is B.

 For cases where we need 3 more equations, such as original conditions with “3 variables”, or “4 variables and 1 equation”, or “5 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 80% chance that E is the answer (especially about 90% of 2 by 2 questions where there are more than 3 variables), while C has 15% chance. These two are the majority. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since E is most likely to be the answer using 1) and 2) separately according to DS definition (It saves us time). Obviously there may be cases where the answer is A, B, C or D.
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Non-Human User
Joined: 09 Sep 2013
Posts: 13421
Re: When k, l, and m are different positive integers greater than 1, k+l+m  [#permalink]

### Show Tags

26 Aug 2018, 21:49
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: When k, l, and m are different positive integers greater than 1, k+l+m   [#permalink] 26 Aug 2018, 21:49
Display posts from previous: Sort by