Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

It is currently 24 May 2017, 14:49

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Good One from MGMAT Q Bank

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
1 KUDOS received
Retired Moderator
User avatar
Status: The last round
Joined: 18 Jun 2009
Posts: 1300
Concentration: Strategy, General Management
GMAT 1: 680 Q48 V34
Followers: 81

Kudos [?]: 1075 [1] , given: 157

GMAT ToolKit User
Good One from MGMAT Q Bank [#permalink]

Show Tags

New post 10 Jul 2010, 23:24
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

25% (01:11) correct 75% (00:44) wrong based on 10 sessions

HideShow timer Statistics

Which of the following best approximates the value of \(q\) if 5^28 + 3^11=5^q ?

A 39
B 30
C 28
D 27
E 17
_________________

[ From 470 to 680-My Story ] [ My Last Month Before Test ]
[ GMAT Prep Analysis Tool ] [ US. Business School Dashboard ] [ Int. Business School Dashboard ]

I Can, I Will

GMAT Club Premium Membership - big benefits and savings

3 KUDOS received
Kaplan GMAT Instructor
User avatar
Joined: 21 Jun 2010
Posts: 74
Location: Toronto
Followers: 30

Kudos [?]: 176 [3] , given: 2

Re: Good One from MGMAT Q Bank [#permalink]

Show Tags

New post 11 Jul 2010, 00:15
3
This post received
KUDOS
Note that the question invites approximation. ("which of the following approximates...?")

That combined with the fact that we are dealing with exponents that are so far apart is a huge signal that you should approach this one qualitatively, reasoning it out and approximating rather than using pure algebra.

If you understand how quickly orders of magnitude increase, then you can reason your way to the right answer very quickly. A number like 5^28 is going to be WAAAAAAY bigger than 3^11. Absolutely, hugely bigger than 3^11. So, 3^11 is negligible, like nothing, compared to 5^28. So, we can look at the equation like this:

5^28 + (nothing) = 5^q
5^28 = 5^q
28 = q

Choose C.
Retired Moderator
User avatar
Status: The last round
Joined: 18 Jun 2009
Posts: 1300
Concentration: Strategy, General Management
GMAT 1: 680 Q48 V34
Followers: 81

Kudos [?]: 1075 [0], given: 157

GMAT ToolKit User
Re: Good One from MGMAT Q Bank [#permalink]

Show Tags

New post 11 Jul 2010, 02:25
Manager
Manager
avatar
Joined: 04 Feb 2010
Posts: 198
Followers: 1

Kudos [?]: 43 [0], given: 8

Re: Good One from MGMAT Q Bank [#permalink]

Show Tags

New post 11 Jul 2010, 03:33
Wow, thanks for the explanation testluv. Been wondering what's the elegant solution to this.
Intern
Intern
User avatar
Joined: 25 Jan 2010
Posts: 17
Followers: 0

Kudos [?]: 0 [0], given: 1

Re: Good One from MGMAT Q Bank [#permalink]

Show Tags

New post 11 Jul 2010, 20:16
Thank you testluv!
Re: Good One from MGMAT Q Bank   [#permalink] 11 Jul 2010, 20:16
Display posts from previous: Sort by

Good One from MGMAT Q Bank

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.