Apr 20 10:00 PM PDT  11:00 PM PDT The Easter Bunny brings … the first day of school?? Yes! Now is the time to start studying for the GMAT if you’re planning to apply to Round 1 of fall MBA programs. Get a special discount with the Easter sale! Apr 21 07:00 AM PDT  09:00 AM PDT Get personalized insights on how to achieve your Target Quant Score. Apr 20 07:00 AM PDT  09:00 AM PDT Christina scored 760 by having clear (ability) milestones and a trackable plan to achieve the same. Attend this webinar to learn how to build trackable milestones that leverage your strengths to help you get to your target GMAT score. Apr 21 10:00 PM PDT  11:00 PM PDT $84 + an extra $10 off for the first month of EMPOWERgmat access. Train to be ready for Round 3 Deadlines with EMPOWERgmat's Score Booster. Ends April 21st Code: GCENHANCED Apr 22 08:00 AM PDT  09:00 AM PDT What people who reach the high 700's do differently? We're going to share insights, tips, and strategies from data we collected on over 50,000 students who used examPAL. Save your spot today! Apr 23 08:00 PM EDT  09:00 PM EDT Strategies and techniques for approaching featured GMAT topics. Tuesday, April 23rd at 8 pm ET Apr 24 08:00 PM EDT  09:00 PM EDT Maximize Your Potential: 5 Steps to Getting Your Dream MBA Part 3 of 5: Key TestTaking Strategies for GMAT. Wednesday, April 24th at 8 pm ET Apr 27 07:00 AM PDT  09:00 AM PDT Attend this webinar and master GMAT SC in 10 days by learning how meaning and logic can help you tackle 700+ level SC questions with ease. Apr 28 07:00 AM PDT  09:00 AM PDT Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 54376

At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
20 Dec 2015, 06:21
Question Stats:
84% (01:37) correct 16% (01:39) wrong based on 174 sessions
HideShow timer Statistics
At a given time, what was the ratio of the number of sailboats to the number of motorboats on Lake X? (1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________



Verbal Forum Moderator
Status: Greatness begins beyond your comfort zone
Joined: 08 Dec 2013
Posts: 2251
Location: India
Concentration: General Management, Strategy
GPA: 3.2
WE: Information Technology (Consulting)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
20 Dec 2015, 07:06
Let the number of sailboats =s number of motorboats = m (1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. 1.25m = 1.1s =>(5/4) m = (11/10)s => s/m = 50/44 = 25/22 Sufficient (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30 sm = 30 or ms = 30 Not sufficient Answer A
_________________
When everything seems to be going against you, remember that the airplane takes off against the wind, not with it.  Henry Ford The Moment You Think About Giving Up, Think Of The Reason Why You Held On So Long +1 Kudos if you find this post helpful



Intern
Joined: 01 Nov 2015
Posts: 36
Location: India
Concentration: Marketing, Entrepreneurship
WE: Engineering (Computer Software)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
23 Dec 2015, 00:27
Skywalker, I can understand the logic you used, but aren't we not allowed to equate sailboats and motorboats to each other?
If s was the initial no^ of sailboats and m was the initial number of motorboats, then, in the original equation, there is no relation given between then^
so, if we assume s#=5/4 s and m#=11/10 m, then #m#s#/m#= (5/4) s / (11/10) m => s# / m# =25s/22m => s/m = 22s#/25m# or 22/25 s#/m#[/m] and in this case, the value of s/m will depend on s#/m# and hence statement I shouldn't be sufficient.
Is this assumption wrong?



Math Expert
Joined: 02 Aug 2009
Posts: 7569

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
23 Dec 2015, 01:32
appsy01 wrote: Skywalker, I can understand the logic you used, but aren't we not allowed to equate sailboats and motorboats to each other?
If s was the initial no^ of sailboats and m was the initial number of motorboats, then, in the original equation, there is no relation given between then^
so, if we assume s#=5/4 s and m#=11/10 m, then #m#s#/m#= (5/4) s / (11/10) m => s# / m# =25s/22m => s/m = 22s#/25m# or 22/25 s#/m#[/m] and in this case, the value of s/m will depend on s#/m# and hence statement I shouldn't be sufficient.
Is this assumption wrong? hi, you are correct prior to the coloured portion.. why are you taking ratio of s# and m#.... its not correct what we require to do is equate both of them due to the statement If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X... so here s#=m#.. or (5/4) s =(11/10) m .... get s and m on one side and you will have s/m and other side you will have the ratio
_________________



Intern
Joined: 01 Nov 2015
Posts: 36
Location: India
Concentration: Marketing, Entrepreneurship
WE: Engineering (Computer Software)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
23 Dec 2015, 09:55
chetan2u wrote: appsy01 wrote: Skywalker, I can understand the logic you used, but aren't we not allowed to equate sailboats and motorboats to each other?
If s was the initial no^ of sailboats and m was the initial number of motorboats, then, in the original equation, there is no relation given between then^
so, if we assume s#=5/4 s and m#=11/10 m, then #m#s#/m#= (5/4) s / (11/10) m => s# / m# =25s/22m => s/m = 22s#/25m# or 22/25 s#/m#[/m] and in this case, the value of s/m will depend on s#/m# and hence statement I shouldn't be sufficient.
Is this assumption wrong? hi, you are correct prior to the coloured portion.. why are you taking ratio of s# and m#.... its not correct what we require to do is equate both of them due to the statement If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X... so here s#=m#.. or (5/4) s =(11/10) m .... get s and m on one side and you will have s/m and other side you will have the ratio Ah! did not register the "would have been" clearly! Thanks a lot for the clarification chetan



Manager
Status: tough ... ? Naaahhh !!!!
Joined: 08 Sep 2015
Posts: 63
Location: India
Concentration: Marketing, Strategy
WE: Marketing (Computer Hardware)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
23 Dec 2015, 10:35
(1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. S=110/110(M+M/4) S/M=8/11 ....Suff (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30. ...MS=30 ....Insuff
Ans: A



Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 7230
GPA: 3.82

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
23 Dec 2015, 19:02
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. At a given time, what was the ratio of the number of sailboats to the number of motorboats on Lake X? (1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30. In the original condition and the question, consider the number of sailboats as ‘s’ and the number of motorboats as ‘m’. Then, you can come up with a question ‘s:m=?.’ However, when a ratio is asked in a question, it is likely that con is the ratio, which is an answer. So, in 1) s=1.1(1.25m), since s:m is unique, it is sufficient. In 2) sm=30, since s:m is not unique, it is not sufficient. Therefore, the answer is A.
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spareThe oneandonly World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy. "Only $149 for 3 month Online Course""Free Resources30 day online access & Diagnostic Test""Unlimited Access to over 120 free video lessons  try it yourself"



Director
Joined: 23 Jan 2013
Posts: 549

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
01 Mar 2016, 04:50
we need to find s/m
St.1 increasing m 1.25 times means that s/m ratio became 1.25 times less than original. So, original ratio was 1.25*1.1=1.375. SUFF
St.2 INSUFF.
A



Manager
Joined: 25 Sep 2015
Posts: 104
Location: United States
GPA: 3.26

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
01 Mar 2016, 17:46
chetan2u wrote: appsy01 wrote: Skywalker, I can understand the logic you used, but aren't we not allowed to equate sailboats and motorboats to each other?
If s was the initial no^ of sailboats and m was the initial number of motorboats, then, in the original equation, there is no relation given between then^
so, if we assume s#=5/4 s and m#=11/10 m, then #m#s#/m#= (5/4) s / (11/10) m => s# / m# =25s/22m => s/m = 22s#/25m# or 22/25 s#/m#[/m] and in this case, the value of s/m will depend on s#/m# and hence statement I shouldn't be sufficient.
Is this assumption wrong? hi, you are correct prior to the coloured portion.. why are you taking ratio of s# and m#.... its not correct what we require to do is equate both of them due to the statement If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X... so here s#=m#.. or (5/4) s =(11/10) m .... get s and m on one side and you will have s/m and other side you will have the ratio hi chetan2uI don't understand your explanation. I deduced x=1.1*1.25*y (since it says if Y is 25%increased, X is 110% of y  Doesn't that mean 1.1*1.25*Y?)



CEO
Joined: 20 Mar 2014
Posts: 2624
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
01 Mar 2016, 17:59
rachitshah wrote: chetan2u wrote: appsy01 wrote: Skywalker, I can understand the logic you used, but aren't we not allowed to equate sailboats and motorboats to each other?
If s was the initial no^ of sailboats and m was the initial number of motorboats, then, in the original equation, there is no relation given between then^
so, if we assume s#=5/4 s and m#=11/10 m, then #m#s#/m#= (5/4) s / (11/10) m => s# / m# =25s/22m => s/m = 22s#/25m# or 22/25 s#/m#[/m] and in this case, the value of s/m will depend on s#/m# and hence statement I shouldn't be sufficient.
Is this assumption wrong? hi, you are correct prior to the coloured portion.. why are you taking ratio of s# and m#.... its not correct what we require to do is equate both of them due to the statement If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X... so here s#=m#.. or (5/4) s =(11/10) m .... get s and m on one side and you will have s/m and other side you will have the ratio hi chetan2uI don't understand your explanation. I deduced x=1.1*1.25*y (since it says if Y is 25%increased, X is 110% of y  Doesn't that mean 1.1*1.25*Y?) You are correct rachitshah. As per the given verbiage of statement 1, the equation if you have to set up will be s=1.1*1.25*m and not 1.25s = 1.1 m . But the main point to note here is that this statement is sufficient to calculate the ratio of s/m at any given time. Hope this helps.



Intern
Joined: 18 Sep 2016
Posts: 37

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
12 Aug 2017, 09:00
Bunuel wrote: At a given time, what was the ratio of the number of sailboats to the number of motorboats on Lake X?
(1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30. Can someone please give a detailed explanation to this problem. why 1.25m=1.1s? The statement says "the number of sailboats on Lake X would have been 110% of the number of motorboats" Doesnt it mean s=1.1m?



CEO
Joined: 20 Mar 2014
Posts: 2624
Concentration: Finance, Strategy
GPA: 3.7
WE: Engineering (Aerospace and Defense)

Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
Show Tags
13 Aug 2017, 05:01
tejasridarsi wrote: Bunuel wrote: At a given time, what was the ratio of the number of sailboats to the number of motorboats on Lake X?
(1) If the number of motorboats on Lake X had been 25% greater, the number of sailboats on Lake X would have been 110% of the number of motorboats on Lake X. (2) The positive difference between the number of motorboats on Lake X and the number of sailboats on Lake X was 30. Can someone please give a detailed explanation to this problem. why 1.25m=1.1s? The statement says "the number of sailboats on Lake X would have been 110% of the number of motorboats" Doesnt it mean s=1.1m? You are only quoting a part of the first statement and ignoring the red part above. This is where 1.25s will come from.




Re: At a given time, what was the ratio of the number of sailboats to the
[#permalink]
13 Aug 2017, 05:01






