Last visit was: 28 Apr 2024, 16:56 It is currently 28 Apr 2024, 16:56

Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
CIO
CIO
Joined: 09 Mar 2003
Posts: 230
Own Kudos [?]: 171 [0]
Given Kudos: 0
Send PM
User avatar
Manager
Manager
Joined: 28 Jun 2004
Posts: 61
Own Kudos [?]: 489 [0]
Given Kudos: 0
Send PM
User avatar
SVP
SVP
Joined: 07 Jul 2004
Posts: 2004
Own Kudos [?]: 1900 [0]
Given Kudos: 0
Location: Singapore
Send PM
User avatar
CIO
CIO
Joined: 09 Mar 2003
Posts: 230
Own Kudos [?]: 171 [0]
Given Kudos: 0
Send PM
Re: How can we do this quickly? [#permalink]
Sorry, my bad completely. The question should read,

"...what is (x/2) + (y/3) in terms of y?"

I'll fix the original post.
User avatar
Manager
Manager
Joined: 25 Dec 2003
Posts: 215
Own Kudos [?]: 60 [0]
Given Kudos: 0
Location: India
Send PM
Re: How can we do this quickly? [#permalink]
If 2x + 3y = 1, what is (x/2) + (y/3) in terms of y?

---> 2x+3y=1
---> 2x=1-3y
---> x= (1-3y)/2
---> x/2=(1-3y)/4

Add y/3 on both sides.....

(x/2)+(y/3)= (1-3y)/4 + (y/3)

---> u get (3-5y)/12

(Solved less than one minute) :)
User avatar
SVP
SVP
Joined: 07 Jul 2004
Posts: 2004
Own Kudos [?]: 1900 [0]
Given Kudos: 0
Location: Singapore
Send PM
Re: How can we do this quickly? [#permalink]
(E). 20 secs. I think good old substitution is still very fast in this case. If you note that you'll end up with 2 and 3 as denominator, you can work two steps ahead while substituting by adjusting the integer value of y as you work throuhg the problem.
avatar
Senior Manager
Senior Manager
Joined: 20 Jul 2004
Posts: 318
Own Kudos [?]: 363 [0]
Given Kudos: 0
Send PM
Re: How can we do this quickly? [#permalink]
I guess solving might be faster than substituting numbers (I mean, if Ian hadn't given the preface).

Let the value be M

2x + 3y = 1
3x + 2y = 6M

Solving this,
-5y = 12M-1
M = (3-5y)/12
User avatar
Manager
Manager
Joined: 18 Jun 2004
Posts: 55
Own Kudos [?]: 374 [0]
Given Kudos: 0
Location: san jose , CA
Send PM
Re: How can we do this quickly? [#permalink]
15 seconds , I got it as E .

divide the existing equation by 4 and move 3y/4 to the right side ,
you know x/2 and then simply add y/3 .

x /2 = (1-3y)/4

x/2 + y/3 = (1-3y)/4 + y/12
= (3-5y)/12
User avatar
Manager
Manager
Joined: 18 Jun 2004
Posts: 55
Own Kudos [?]: 374 [0]
Given Kudos: 0
Location: san jose , CA
Send PM
Re: How can we do this quickly? [#permalink]
Infact the moment you see the denominator as 12 , you can choose the choice E , because there is no other choice which has denominator 12 .

My bad , if i had not overlooked the choices , i think this problem can be solved with in 15 seconds .
User avatar
Intern
Intern
Joined: 22 Mar 2004
Posts: 13
Own Kudos [?]: [0]
Given Kudos: 0
Location: TX
Send PM
Re: How can we do this quickly? [#permalink]
hardworker_indian wrote:
I guess solving might be faster than substituting numbers (I mean, if Ian hadn't given the preface).

Let the value be M

2x + 3y = 1
3x + 2y = 6M

Solving this,
-5y = 12M-1
M = (3-5y)/12

This is probably one of the most straightforward way of solving the equation!



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
Re: How can we do this quickly? [#permalink]
Moderator:
Senior Moderator - Masters Forum
3137 posts

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