It is currently 18 Nov 2017, 10:55

### 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

# If a^6 - b^6 = 0, what is the value of a^3 - b^3? (1) b is

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Senior Manager
Joined: 17 May 2005
Posts: 270

Kudos [?]: 19 [0], given: 0

Location: Auckland, New Zealand
If a^6 - b^6 = 0, what is the value of a^3 - b^3? (1) b is [#permalink]

### Show Tags

07 Jun 2005, 02:20
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 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^6 - b^6 = 0, what is the value of a^3 - b^3?

(1) b is greater than 1
(2) a is positive

Kudos [?]: 19 [0], given: 0

Director
Joined: 07 Jun 2004
Posts: 610

Kudos [?]: 948 [0], given: 22

Location: PA

### Show Tags

07 Jun 2005, 03:38
sin e we have to find the value the answer to this is E

Kudos [?]: 948 [0], given: 22

Senior Manager
Joined: 17 Apr 2005
Posts: 372

Kudos [?]: 30 [0], given: 0

Location: India

### Show Tags

07 Jun 2005, 07:40
cloudz9 wrote:
If a^6 - b^6 = 0, what is the value of a^3 - b^3?

(1) b is greater than 1
(2) a is positive

C.

using (1) and (2) we know that a^3 + b^3 is not zero. Hence a^3 - b^3 should be zero.

HMTG.

Kudos [?]: 30 [0], given: 0

Director
Joined: 07 Jun 2004
Posts: 610

Kudos [?]: 948 [0], given: 22

Location: PA

### Show Tags

07 Jun 2005, 08:57
u r right since both a and b are +ve the value of a^3 - b^3 will always be zero

Kudos [?]: 948 [0], given: 22

Senior Manager
Joined: 21 Mar 2004
Posts: 445

Kudos [?]: 76 [0], given: 0

Location: Cary,NC

### Show Tags

07 Jun 2005, 11:45
a^6 - b^6 = 0

implies (a^3+b^3)(a^3 - b^3) = 0

A &B are insufficient as knowing value of only 1 variable is not enough to show that (a^3+b^3) is +ve

C. both a,b >0
so
(a^3+b^3) >0
so
(a^3-b^3) must = 0

sifficient
_________________

ash
________________________
I'm crossing the bridge.........

Kudos [?]: 76 [0], given: 0

Intern
Joined: 30 May 2005
Posts: 29

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

### Show Tags

15 Jun 2005, 03:42
My answer is C.

Statement 1: Insufficent. A and D options are ruled out.
Stetament 2: Insufficient. B is ruled out.

Combined together, we conclude that A and B are both are positive hence a^3 + b^3 can not be zero. This forces a^3 - b^3 to be zero. Hence C.

Note : a^6 - b^6= (a^3 + b^3 ) (a^3 - b^3 )

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

15 Jun 2005, 03:42
Display posts from previous: Sort by

# If a^6 - b^6 = 0, what is the value of a^3 - b^3? (1) b is

 post reply Question banks Downloads My Bookmarks Reviews Important topics

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