Last visit was: 14 Dec 2024, 07:38 It is currently 14 Dec 2024, 07:38
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
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Dec 2024
Posts: 97,874
Own Kudos:
Given Kudos: 88,270
Products:
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 97,874
Kudos: 685,781
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
Vinayak Shenoy
Joined: 06 Jun 2016
Last visit: 27 Jun 2017
Posts: 233
Own Kudos:
Given Kudos: 212
Location: India
Concentration: Operations, Strategy
Schools: ISB '18 (D)
GMAT 1: 600 Q49 V23
GMAT 2: 680 Q49 V34
GPA: 3.9
Schools: ISB '18 (D)
GMAT 2: 680 Q49 V34
Posts: 233
Kudos: 114
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
georgekaterji
Joined: 23 Oct 2016
Last visit: 24 Feb 2020
Posts: 23
Own Kudos:
Given Kudos: 17
Posts: 23
Kudos: 12
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
mvictor
User avatar
Board of Directors
Joined: 17 Jul 2014
Last visit: 14 Jul 2021
Posts: 2,136
Own Kudos:
1,219
 []
Given Kudos: 236
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE:General Management (Transportation)
Products:
GMAT 1: 650 Q49 V30
Posts: 2,136
Kudos: 1,219
 []
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Bunuel
If a, b, and c are integers, is abc divisible by 8?

(1) a and b are even integers.
(2) a, b, and c are consecutive multiples of 2

to be divisible by 8, the number must have 3 factors of 2.

1. a and b are even
since we don't know whether a and b are different integers, we can assume that both of them are 2.
c might be odd integer.
in this case, abc is not divisible by 8.
but, if a =2, b=4, and regardless of what c is, we know for sure that it's divisible by 8.
A and D are out.

2. a,b,c are consecutive multiples of 2.
suppose a=2, b=4, c=6 - abc divisible by 8
what if one of the numbers is negative or one of the numbers is zero?
if a=-2, then b=0, and c=2. abc=0, which is divisible by 8...
in any case, statement 2 alone is sufficient.

answer is B.
User avatar
GMATinsight
User avatar
GMAT Club Legend
Joined: 08 Jul 2010
Last visit: 13 Dec 2024
Posts: 6,074
Own Kudos:
Given Kudos: 125
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Products:
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,074
Kudos: 14,607
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If a, b, and c are integers, is abc divisible by 8?

(1) a and b are even integers.
(2) a, b, and c are consecutive multiples of 2

Question : Is abc divisible by 8?

Statement 1:: a and b are even integers
Case 1: a = 2 and b = 6 and c=3 and abc is NOT divisible by 8
Case 2: a = 2 and b = 4 and c=3 and abc is divisible by 8, Hence
NOT SUFFICIENT

Statement 2:: a, b, and c are consecutive multiples of 2
IMPORTANT: Any Two consecutive multiples of 2 contain one multiple of 2 and other multiple of 4 at least
i.e. product of two consecutive multiples of 2 is always divisible by 2*=8
i.e. 2*4=8
and 4*6=24
and 6*8=48 etc, Hence
SUFFICIENT



Answer: Option B
User avatar
stonecold
Joined: 12 Aug 2015
Last visit: 09 Apr 2024
Posts: 2,261
Own Kudos:
Given Kudos: 893
GRE 1: Q169 V154
GRE 1: Q169 V154
Posts: 2,261
Kudos: 3,300
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Nice Question.
Here is what i did on this one =>
We need to see if a*b*c is divisible by 8 or not.
Statement 1->
a=even
b=even
a=2
b=2
c=1
=> NO
a=2
b=2
c=2
YES
Hence not sufficient.

Statement 2=>
As they are some multiples of 2 => All are even => a*b*c must be a multiple of 8.
Hehe sufficient.
Hone B.
Moderator:
Math Expert
97874 posts