Last visit was: 26 Apr 2026, 19:01 It is currently 26 Apr 2026, 19:01
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
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 26 Apr 2026
Posts: 11,229
Own Kudos:
45,025
 [5]
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,229
Kudos: 45,025
 [5]
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
User avatar
GMATinsight
User avatar
Major Poster
Joined: 08 Jul 2010
Last visit: 26 Apr 2026
Posts: 6,977
Own Kudos:
Given Kudos: 128
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
Expert reply
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,977
Kudos: 16,922
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 26 Apr 2026
Posts: 8,631
Own Kudos:
5,191
 [1]
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
Products:
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,631
Kudos: 5,191
 [1]
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 26 Apr 2026
Posts: 8,631
Own Kudos:
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
Products:
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,631
Kudos: 5,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATinsight
sir in #1 what about -ve pairs ; -3,-5 ...

GMATinsight
chetan2u
If A and B are single digits and their sum is a multiple of 5, what is the value of A+B?
(I) The 2-digit number AB is a multiple of 3.
(II) A is a multiple of 9.

\((a+b)_{max} = 9+9 = 18\)

i.e. a+b can be {5, 10, 15}

Question: a+b =?

Statement 1: The 2-digit number AB is a multiple of 3.

A number is divisible by 3 only if the sum of the digits is divisible by 3



Now, sum must be a multiple of 5 less than 18 and sum must be a multiple of 3 i.e. a+b can be only 15

i.e ab = {69, 78, 87, 96}

But a+b for all combinations = 15 hence

SUFFICIENT

STatement 2: a = 9

b may be 1 or 7 both for sum a+b to be a multiple of 5 hence

NOT SUFFICIENT

ANswer: Option A
User avatar
GMATinsight
User avatar
Major Poster
Joined: 08 Jul 2010
Last visit: 26 Apr 2026
Posts: 6,977
Own Kudos:
16,922
 [1]
Given Kudos: 128
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
Expert reply
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
Posts: 6,977
Kudos: 16,922
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Archit3110
GMATinsight
sir in #1 what about -ve pairs ; -3,-5 ...

GMATinsight
chetan2u
If A and B are single digits and their sum is a multiple of 5, what is the value of A+B?
(I) The 2-digit number AB is a multiple of 3.
(II) A is a multiple of 9.

\((a+b)_{max} = 9+9 = 18\)

i.e. a+b can be {5, 10, 15}

Question: a+b =?

Statement 1: The 2-digit number AB is a multiple of 3.

A number is divisible by 3 only if the sum of the digits is divisible by 3



Now, sum must be a multiple of 5 less than 18 and sum must be a multiple of 3 i.e. a+b can be only 15

i.e ab = {69, 78, 87, 96}

But a+b for all combinations = 15 hence

SUFFICIENT

STatement 2: a = 9

b may be 1 or 7 both for sum a+b to be a multiple of 5 hence

NOT SUFFICIENT

ANswer: Option A

Archit3110

The digits of a two-digit number can NOT be negative
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 26 Apr 2026
Posts: 11,229
Own Kudos:
45,025
 [1]
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,229
Kudos: 45,025
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Archit3110
GMATinsight
sir in #1 what about -ve pairs ; -3,-5 ...

GMATinsight
chetan2u
If A and B are single digits and their sum is a multiple of 5, what is the value of A+B?
(I) The 2-digit number AB is a multiple of 3.
(II) A is a multiple of 9.

\((a+b)_{max} = 9+9 = 18\)

i.e. a+b can be {5, 10, 15}

Question: a+b =?

Statement 1: The 2-digit number AB is a multiple of 3.

A number is divisible by 3 only if the sum of the digits is divisible by 3



Now, sum must be a multiple of 5 less than 18 and sum must be a multiple of 3 i.e. a+b can be only 15

i.e ab = {69, 78, 87, 96}

But a+b for all combinations = 15 hence

SUFFICIENT

STatement 2: a = 9

b may be 1 or 7 both for sum a+b to be a multiple of 5 hence

NOT SUFFICIENT

ANswer: Option A

GMATinsight has just answered that ...
Also when we talk of digits, they can be only 10 :- ( 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 26 Apr 2026
Posts: 8,631
Own Kudos:
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
Products:
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,631
Kudos: 5,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATinsight
my bad ... :-o

GMATinsight
Archit3110
GMATinsight
sir in #1 what about -ve pairs ; -3,-5 ...

GMATinsight
chetan2u
If A and B are single digits and their sum is a multiple of 5, what is the value of A+B?
(I) The 2-digit number AB is a multiple of 3.
(II) A is a multiple of 9.

\((a+b)_{max} = 9+9 = 18\)

i.e. a+b can be {5, 10, 15}

Question: a+b =?

Statement 1: The 2-digit number AB is a multiple of 3.

A number is divisible by 3 only if the sum of the digits is divisible by 3



Now, sum must be a multiple of 5 less than 18 and sum must be a multiple of 3 i.e. a+b can be only 15

i.e ab = {69, 78, 87, 96}

But a+b for all combinations = 15 hence

SUFFICIENT

STatement 2: a = 9

b may be 1 or 7 both for sum a+b to be a multiple of 5 hence

NOT SUFFICIENT

ANswer: Option A

Archit3110

The digits of a two-digit number can NOT be negative
User avatar
Archit3110
User avatar
Major Poster
Joined: 18 Aug 2017
Last visit: 26 Apr 2026
Posts: 8,631
Own Kudos:
Given Kudos: 243
Status:You learn more from failure than from success.
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1: 545 Q79 V79 DI73
GMAT Focus 2: 645 Q83 V82 DI81
GPA: 4
WE:Marketing (Energy)
Products:
GMAT Focus 2: 645 Q83 V82 DI81
Posts: 8,631
Kudos: 5,191
Kudos
Add Kudos
Bookmarks
Bookmark this Post
chetan2u
really a good DS trap question ... at least for me :D ...

chetan2u
Archit3110
GMATinsight
sir in #1 what about -ve pairs ; -3,-5 ...

GMATinsight
chetan2u
If A and B are single digits and their sum is a multiple of 5, what is the value of A+B?
(I) The 2-digit number AB is a multiple of 3.
(II) A is a multiple of 9.

\((a+b)_{max} = 9+9 = 18\)

i.e. a+b can be {5, 10, 15}

Question: a+b =?

Statement 1: The 2-digit number AB is a multiple of 3.

A number is divisible by 3 only if the sum of the digits is divisible by 3



Now, sum must be a multiple of 5 less than 18 and sum must be a multiple of 3 i.e. a+b can be only 15

i.e ab = {69, 78, 87, 96}

But a+b for all combinations = 15 hence

SUFFICIENT

STatement 2: a = 9

b may be 1 or 7 both for sum a+b to be a multiple of 5 hence

NOT SUFFICIENT

ANswer: Option A

GMATinsight has just answered that ...
Also when we talk of digits, they can be only 10 :- ( 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,992
Own Kudos:
Posts: 38,992
Kudos: 1,118
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109910 posts
498 posts
212 posts