Last visit was: 25 Apr 2026, 01:16 It is currently 25 Apr 2026, 01:16
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: 24 Apr 2026
Posts: 109,822
Own Kudos:
811,115
 [1]
Given Kudos: 105,878
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,822
Kudos: 811,115
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
yezz
User avatar
Retired Moderator
Joined: 05 Jul 2006
Last visit: 26 Apr 2022
Posts: 830
Own Kudos:
1,687
 [1]
Given Kudos: 49
Posts: 830
Kudos: 1,687
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
zahinsarwar
Joined: 16 Mar 2017
Last visit: 09 Sep 2018
Posts: 8
Own Kudos:
Given Kudos: 505
Location: Bangladesh
Concentration: Finance, Accounting
GMAT 1: 610 Q47 V27
GPA: 3.71
WE:Accounting (Other)
GMAT 1: 610 Q47 V27
Posts: 8
Kudos: 2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
MathRevolution
User avatar
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Last visit: 27 Sep 2022
Posts: 10,063
Own Kudos:
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Expert
Expert reply
GMAT 1: 760 Q51 V42
Posts: 10,063
Kudos: 20,002
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
If a and b are non-negative integers and a/b is an integer, is b divisible by a?

(1) a = 12
(2) b is a multiple of 12


Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.


We can assume 2 variables and 1 equation. Thus C could be the answer most likely.

Condition 1) \(a = 12\)
This condition alone is not sufficient, since there is no information about \(b\).

Condition 2) \(b = 12k\) for some integer \(k\)
This condition alone is not sufficient, since there is no information about \(a\).

Condition 1) & 2)

Since \(b = 12k\) for some integer \(k\), \(b/a = 12k/12 = k\), which is an integer.
Thus \(b\) is divisible by \(a\).

Both conditions together are sufficient.

Therefore, C is the answer as expected.

Normally for cases where we need 2 more equations, such as original conditions with 2 variables, or 3 variables and 1 equation, or 4 variables and 2 equations, we have 1 equation each in both 1) and 2). Therefore C has a high chance of being the answer, which is why we attempt to solve the question using 1) and 2) together. Here, there is 70% chance that C is the answer, while E has 25% chance. These two are the key questions. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since C is most likely to be the answer according to DS definition, we solve the question assuming C would be our answer hence using 1) and 2) together. (It saves us time). Obviously there may be cases where the answer is A, B, D or E.
Moderators:
Math Expert
109822 posts
498 posts
212 posts