GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 10 Dec 2018, 18:29

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
Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • Free lesson on number properties

     December 10, 2018

     December 10, 2018

     10:00 PM PST

     11:00 PM PST

    Practice the one most important Quant section - Integer properties, and rapidly improve your skills.
  • Free GMAT Prep Hour

     December 11, 2018

     December 11, 2018

     09:00 PM EST

     10:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. December 11 at 9 PM EST.

If a = 2,879 + b, what is the value of the digit b?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51072
If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 08 Jul 2018, 23:50
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

27% (01:13) correct 73% (01:20) wrong based on 55 sessions

HideShow timer Statistics

Director
Director
User avatar
P
Status: Learning stage
Joined: 01 Oct 2017
Posts: 931
WE: Supply Chain Management (Energy and Utilities)
Premium Member
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 00:34
Bunuel wrote:
If a = 2,879 + b, what is the value of the digit b?

(1) a is divisible by 7.
(2) a is divisible by 2.


Given a = 2,879 + b
We have range of 'b' from -9 to 9 since 'b' is a digit.
So, 'a' ranges from 2879-9 to 2879+9, i.e, 2870 to 2889.
Question stem: b=?

st1:-a is divisible by 7

So a=2870,2877, and 2884 when b=-9, -2, and 5 respectively.

Since b has more than one values, hence insufficient.

st2:-a is divisible by 2
So a=2870,2872, .......,2884,2886,2888 when b=-9, -7,.......,5,7,9 respectively.
Since b has more than one values, hence insufficient.
Now, combining st1 and st2, we have
a=2870 and 2884 when b=-9 and 5 respectively.
Since b has more than one values, hence insufficient.

Hence, insufficient.

Ans. (E)
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Director
Director
User avatar
P
Joined: 14 Dec 2017
Posts: 519
Location: India
Premium Member
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 08:43
3
Bunuel wrote:
If a = 2,879 + b, what is the value of the digit b?

(1) a is divisible by 7.
(2) a is divisible by 2.



Given a = 2879 + b, b is a digit, b = {0,1,......8,9}

We have find value of digit b = ?

Statement 1: a is divisible by 7

Hence, (2879 + b) is divisible by 7

When 2879 is divided by 7, we get remainder as 2.

So for a to be a multiple of 7, (2+b) = 7k

b = 5, 12, 19,....

Statement 1 is Sufficient


Statement 2: a is divisible by 2

Hence, (2879 + b) is divisible by 2

When 2879 is divided by 2, we get remainder as 1.

So for a to be a multiple of 2, (1+b) = 2k

b = 1, 3, 5, 7, 9....

Statement 2 is Not Sufficient.




Answer A.



Thanks,
GyM
_________________

New to GMAT Club - https://gmatclub.com/forum/new-to-gmat-club-need-help-271131.html#p2098335

Director
Director
User avatar
P
Joined: 14 Dec 2017
Posts: 519
Location: India
Premium Member
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 08:47
PKN wrote:
Bunuel wrote:
If a = 2,879 + b, what is the value of the digit b?

(1) a is divisible by 7.
(2) a is divisible by 2.


Given a = 2,879 + b
We have range of 'b' from -9 to 9 since 'b' is a digit.
So, 'a' ranges from 2879-9 to 2879+9, i.e, 2870 to 2889.
Question stem: b=?

st1:-a is divisible by 7

So a=2870,2877, and 2884 when b=-9, -2, and 5 respectively.

Since b has more than one values, hence insufficient.

st2:-a is divisible by 2
So a=2870,2872, .......,2884,2886,2888 when b=-9, -7,.......,5,7,9 respectively.
Since b has more than one values, hence insufficient.
Now, combining st1 and st2, we have
a=2870 and 2884 when b=-9 and 5 respectively.
Since b has more than one values, hence insufficient.

Hence, insufficient.

Ans. (E)


PKN are digits considered to be negative as well?

I thought in decimal system we consider digits to be {0 to 9}. If they are considered negative as well, then good job on the solution. E is the right answer.


Thanks,
GyM
_________________

New to GMAT Club - https://gmatclub.com/forum/new-to-gmat-club-need-help-271131.html#p2098335

Intern
Intern
avatar
B
Joined: 30 Aug 2016
Posts: 6
Concentration: Marketing, Finance
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 08:55
Bunuel wrote:
If a = 2,879 + b, what is the value of the digit b?

(1) a is divisible by 7.
(2) a is divisible by 2.




It is given that that b is a digit. This implies b={0,1,2,...,9}

Conisder
Statement 1:
a is divisible by 7 implies a=((2877) + 2+b)/7 yields a whole number

(2+b)/7 = an integer i.e, when b is 5.

Hence, Statement 1 is sufficient.
Statement 2:
a is divisible by 2 implies a=((2879) + 1+b)/2 yields a whole number

(1+b)/2 = an integer i.e, when b is {1,3,5,7,9}.

That gives multiple solutions. Hence, Insufficient.

The answer has to be A.
Director
Director
User avatar
P
Status: Learning stage
Joined: 01 Oct 2017
Posts: 931
WE: Supply Chain Management (Energy and Utilities)
Premium Member
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 09:03
GyMrAT wrote:
PKN wrote:
Bunuel wrote:
If a = 2,879 + b, what is the value of the digit b?

(1) a is divisible by 7.
(2) a is divisible by 2.


Given a = 2,879 + b
We have range of 'b' from -9 to 9 since 'b' is a digit.
So, 'a' ranges from 2879-9 to 2879+9, i.e, 2870 to 2889.
Question stem: b=?

st1:-a is divisible by 7

So a=2870,2877, and 2884 when b=-9, -2, and 5 respectively.

Since b has more than one values, hence insufficient.

st2:-a is divisible by 2
So a=2870,2872, .......,2884,2886,2888 when b=-9, -7,.......,5,7,9 respectively.
Since b has more than one values, hence insufficient.
Now, combining st1 and st2, we have
a=2870 and 2884 when b=-9 and 5 respectively.
Since b has more than one values, hence insufficient.

Hence, insufficient.

Ans. (E)


PKN are digits considered to be negative as well?

I thought in decimal system we consider digits to be {0 to 9}. If they are considered negative as well, then good job on the solution. E is the right answer.


Thanks,
GyM


Hi GyMrAT,
You are correct . In decimal system digits are from 0-9.
However, since 'b' is involved in an arithmetic operation (a=2879+b), I considered both faces of polarity.
If we go by words of the question stem, it says "what is the value of digit b",then negative digits are not allowed.
Bunuel, chetan2u Could you please clarify?

Thanking you.
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Intern
Intern
User avatar
B
Status: GMAT in August 2018
Joined: 05 Mar 2018
Posts: 46
Location: India
Concentration: Leadership, Strategy
WE: Law (Consulting)
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 10:08
Can “digit” B be negative? I’m unsure. Experts to clarify please.


Sent from my iPhone using GMAT Club Forum
Director
Director
User avatar
P
Status: Learning stage
Joined: 01 Oct 2017
Posts: 931
WE: Supply Chain Management (Energy and Utilities)
Premium Member
If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 18:37
jayantbakshi wrote:
Can “digit” B be negative? I’m unsure. Experts to clarify please.


Sent from my iPhone using GMAT Club Forum


OA is A.Good learnings for me.
I need to revise concepts and start again.

Thank you all.

Posted from my mobile device
_________________

Regards,

PKN

Rise above the storm, you will find the sunshine

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51072
Re: If a = 2,879 + b, what is the value of the digit b?  [#permalink]

Show Tags

New post 09 Jul 2018, 19:49
PKN wrote:
jayantbakshi wrote:
Can “digit” B be negative? I’m unsure. Experts to clarify please.


Sent from my iPhone using GMAT Club Forum


OA is A.Good learnings for me.
I need to revise concepts and start again.

Thank you all.

Posted from my mobile device


Stem says that b is a digit. Digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

GMAT Club Bot
Re: If a = 2,879 + b, what is the value of the digit b? &nbs [#permalink] 09 Jul 2018, 19:49
Display posts from previous: Sort by

If a = 2,879 + b, what is the value of the digit b?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.