It is currently 23 Feb 2018, 02:49

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

OG 11 PS #173

Author Message
Intern
Joined: 02 Mar 2008
Posts: 4

Show Tags

07 Mar 2009, 01:09
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If a/b = 2/3, which of the following is NOT true?

(A) (a+b)/b = 5/3

(B) b/(b-a) = 3

(C) (a-b)/b = 1/3

(D) 2a/3b = 4/9

(E) (a+3b)/a = 11/2

The OG's method of solving this is slightly involved. But...assuming a question like this, in which the answer choices do *not* have any exponents, one could just directly substitute a in for 2, and b in for 3...always, ...right?
Manager
Joined: 28 Jul 2004
Posts: 135
Location: Melbourne
Schools: Yale SOM, Tuck, Ross, IESE, HEC, Johnson, Booth
Re: OG 11 PS #173 [#permalink]

Show Tags

07 Mar 2009, 02:53
Let a=2 and b=3 (since a/b = 2/3)

a+3b/a = 2+9/2 = 11/2 ----> hence true

option (D)
2a/3b = 4/9 --> hence correct

option (C)
(a-b)/b = 2-3/3 = -1/3 ---> hence "Not True"

_________________

kris

VP
Joined: 18 May 2008
Posts: 1258
Re: OG 11 PS #173 [#permalink]

Show Tags

07 Mar 2009, 03:35
why cant we directly substitute values if we have exponents in answers?
mmace1 wrote:
If a/b = 2/3, which of the following is NOT true?

(A) (a+b)/b = 5/3

(B) b/(b-a) = 3

(C) (a-b)/b = 1/3

(D) 2a/3b = 4/9

(E) (a+3b)/a = 11/2

The OG's method of solving this is slightly involved. But...assuming a question like this, in which the answer choices do *not* have any exponents, one could just directly substitute a in for 2, and b in for 3...always, ...right?
Re: OG 11 PS #173   [#permalink] 07 Mar 2009, 03:35
Display posts from previous: Sort by