What is the total number of coins that Bert and Claire have? : GMAT Data Sufficiency (DS)
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

It is currently 03 Dec 2016, 15:54
GMAT Club Tests

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the total number of coins that Bert and Claire have?

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

Hide Tags

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 35843
Followers: 6830

Kudos [?]: 89752 [0], given: 10381

What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 15 Oct 2012, 03:53
Expert's post
16
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (02:14) correct 30% (01:09) wrong based on 862 sessions

HideShow timer Statistics

What is the total number of coins that Bert and Claire have?

(1) Bert has 50 percent more coins than Claire.
(2) The total number of coins that Bert and Claire have is between 21 and 28.

Practice Questions
Question: 65
Page: 280
Difficulty: 600
[Reveal] Spoiler: OA

_________________

New to the Math Forum?
Please read this: 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

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 35843
Followers: 6830

Kudos [?]: 89752 [1] , given: 10381

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 15 Oct 2012, 03:53
1
This post received
KUDOS
Expert's post
3
This post was
BOOKMARKED
SOLUTION

What is the total number of coins that Bert and Claire have?

Question: \(B+C=?\)

(1) Bert has 50 percent more coins than Claire --> \(B=1.5C\). Not sufficient.

(2) The total number of coins that Bert and Claire have is between 21 and 28 --> \(21<B+C<28\). Not sufficient.

(1)+(2) Since from (1) \(B=1.5C\) and from (2) \(21<B+C<28\), then \(21<1.5C+C<28\) --> \(21<2.5C<28\). Three values of C satsify this inequality; 9, 10, and 11. But for 9 and 11, the value of B from \(B=1.5C.\) won't be an integer, thus C can only be 10 --> \(B=1.5C=15\) --> \(B+C=25\). Sufficient.

Answer: C.
_________________

New to the Math Forum?
Please read this: 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

7 KUDOS received
Director
Director
avatar
Joined: 24 Aug 2009
Posts: 504
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 17

Kudos [?]: 663 [7] , given: 241

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 15 Oct 2012, 03:59
7
This post received
KUDOS
1
This post was
BOOKMARKED
1) Let of no of coins with Claire = 2x
Let of no of coins with Bert = 3x
2x+3x = 5x --->x can take any value - Insufficient

2) No of coins can take any integer value from 21 to 28- Insufficient

1+2) Total no of coins must be a multiple of 5 & between 21 & 28. Only possible integer value is 25--->Sufficient
Answer C
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth
-Game Theory

If you have any question regarding my post, kindly pm me or else I won't be able to reply

3 KUDOS received
Manager
Manager
avatar
Joined: 29 Apr 2012
Posts: 104
Location: United States
Concentration: International Business, Real Estate
GMAT Date: 10-22-2012
Followers: 0

Kudos [?]: 54 [3] , given: 47

GMAT ToolKit User
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 15 Oct 2012, 05:39
3
This post received
KUDOS
1
This post was
BOOKMARKED
Bunuel wrote:
What is the total number of coins that Bert and Claire have?

(1) Bert has 50 percent more coins than Claire.
(2) The total number of coins that Bert and Claire have is between 21 and 28.



let the total number of coins be t.
Stamnt A: B = 1.5C --> not sufficient
Statment B: 21<B+C <28

usinng both:
T = B+C = c+1.5c =2.5c
now: anythig between 21 and 28 which is a multiple of 2.5 is 22.5/25/27.5

Since coins cannot be in decimal points , we are left with only one option that is t=25.
thus, OA: C
using both A and B together


Whats the OA?
1 KUDOS received
Moderator
Moderator
User avatar
Joined: 02 Jul 2012
Posts: 1231
Location: India
Concentration: Strategy
GMAT 1: 740 Q49 V42
GPA: 3.8
WE: Engineering (Energy and Utilities)
Followers: 115

Kudos [?]: 1358 [1] , given: 116

Premium Member
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 15 Oct 2012, 08:44
1
This post received
KUDOS
1) Bert can have 10, Claire can have 15 OR Bert can have 20, Claire can have 30. Not sufficient.
2) Clearly not sufficient

Both together

1.5 B + B = 2.5 B= x.

The only number in the range to give an integer value for B is 25.

So, answer is C
_________________

Did you find this post helpful?... Please let me know through the Kudos button.

Thanks To The Almighty - My GMAT Debrief

GMAT Reading Comprehension: 7 Most Common Passage Types

2 KUDOS received
Manager
Manager
avatar
Joined: 21 Sep 2012
Posts: 237
Followers: 1

Kudos [?]: 324 [2] , given: 63

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 16 Oct 2012, 04:47
2
This post received
KUDOS
We need to find out B + C

statement 1

B=0.5C+C

insufficient can't get a value

statement 2

21<B+C<28 again no value insufficient

combining 1 and 2

21<1.5C+C<28
21<2.5C<28 ( multiply by 2)
42<5C<56

so now the values for 5c are the multiples between 42 and 56 so we have 3 values

5C=45 >>> C=9
5C=50 >>> C=10
5C=55 >>> C=11

but we need to satisfy the condition that B=1.5C this is only possible when C = 10 since we need an integer value so 11 and 9 are ruled out

B+C=10+15=25

So the answer is C.
2 KUDOS received
Director
Director
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 647
Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
Followers: 45

Kudos [?]: 539 [2] , given: 23

GMAT ToolKit User Premium Member Reviews Badge
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 16 Oct 2012, 05:04
2
This post received
KUDOS
If Bert has B coins and Claire has C coins. Then total number of coins =B+C

From Statement 1
B =1.5 C or B/C=3/2
Ratio of B and C is 3:2 => Only inference from this we can make is, total number must be a multiple of 5.
Not sufficient

From statement 2
21<=B+C<=28
Multiple values for B+C - not sufficient

Combining the information from statement 1 and 2.
Total number of coins = 25

Hence C.
Bunuel wrote:
What is the total number of coins that Bert and Claire have?

(1) Bert has 50 percent more coins than Claire.
(2) The total number of coins that Bert and Claire have is between 21 and 28.

Practice Questions
Question: 65
Page: 280
Difficulty: 600

_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 35843
Followers: 6830

Kudos [?]: 89752 [0], given: 10381

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 19 Oct 2012, 04:46
SOLUTION

What is the total number of coins that Bert and Claire have?

Question: \(B+C=?\)

(1) Bert has 50 percent more coins than Claire --> \(B=1.5C\). Not sufficient.

(2) The total number of coins that Bert and Claire have is between 21 and 28 --> \(21<B+C<28\). Not sufficient.

(1)+(2) Since from (1) \(B=1.5C\) and from (2) \(21<B+C<28\), then \(21<1.5C+C<28\) --> \(21<2.5C<28\). Three values of C satsify this inequality; 9, 10, and 11. But for 9 and 11, the value of B from \(B=1.5C.\) won't be an integer, thus C can only be 10 --> \(B=1.5C=15\) --> \(B+C=25\). Sufficient.

Answer: C.

Kudos points given to everyone with correct solution. Let me know if I missed someone.
_________________

New to the Math Forum?
Please read this: 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 Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 12855
Followers: 559

Kudos [?]: 157 [0], given: 0

Premium Member
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 25 Nov 2013, 10:18
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Manager
Manager
User avatar
Joined: 12 Jan 2013
Posts: 244
Followers: 4

Kudos [?]: 68 [0], given: 47

GMAT ToolKit User
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 10 Jan 2014, 07:51
Bunuel wrote:
What is the total number of coins that Bert and Claire have?

(1) Bert has 50 percent more coins than Claire.
(2) The total number of coins that Bert and Claire have is between 21 and 28.

Practice Questions
Question: 65
Page: 280
Difficulty: 600


The stem asks us: B + C = TC, what is TC?

1) This tells us that B = 1.5 C, so now we have two unknowns: 2.5C = TC, insufficient
2) Gives us a range of possible values, so in itself 2 is insufficient because the value could be any of 6 values. Insufficient

1 + 2 : Look closely: given our equation from 1, TC must be a multiple of 5 (we cannot have fractions of coins), and given the restriction in 2, we only have ONE possible multiple of 5: 25...

So, TC = 25... Answer is C.
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 12855
Followers: 559

Kudos [?]: 157 [0], given: 0

Premium Member
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 12 Mar 2015, 01:27
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Expert Post
1 KUDOS received
EMPOWERgmat Instructor
User avatar
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 7967
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 358

Kudos [?]: 2367 [1] , given: 163

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 12 Mar 2015, 17:07
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
Hi All,

On Test Day, you're going to face a few questions in the Quant section that are perfect for "brute force" - you don't have to be a genius to get the correct answer and you don't need to have any specialized knowledge either. You DO have to put pen to pad and do some basic work though.

Here, we're asked for the total number of coins that Bert and Clair have.

Fact 1: Bert has 50 percent more coins than Claire.

Since you can't have a "fraction" of a coin, this piece of information provides just a little bit of info about the relationship between the number of coins that Bert has and the number of coins that Claire has.

IF.....
Claire has 1 coin, Bert has 1.5 coins, which does NOT make sense (he can't have half a coin).
Claire has 2 coins, then Bert has 3 coins. THIS makes sense. The total is 5 coins.
Claire has 4 coins, then bert has 6 coins. This also makes sense. The total is 10 coins.
Fact 1 is INSUFFICIENT.

You may have noticed that the total number of coins is going to be a multiple of 5. You don't need to know that to answer the question (although it would likely save you some time later on).

Fact 2: The total number of coins that Bert and Claire have is between 21 and 28.

This gives us more direct information, but no exact value.
Fact 2 is INSUFFICIENT.

Combined, we know....
Bert has 50 percent more coins than Claire.
The total number of coins that Bert and Claire have is between 21 and 28.

From here, you can "map out" the possibilities....
We already know that Claire MUST have an EVEN number of coins....so let's start there....

IF...
Claire = 6, then Bert = 9 and the total is 15. This does not fit the given range, so it can't be the answer.
Claire = 8, then Bert = 12 and the total is 20. This does not fit the given range, so it can't be the answer.
Claire = 10, then Bert = 15 and the total is 25. This DOES fit the given range, so it COULD be the answer.
Claire = 12, then Bert = 18 and the total is 30. This does not fit the given range, so it can't be the answer.

As the number of coins Claire has increases, then the total will increase (and continue to be out of the given range). This means that there's JUST ONE answer that fits all of the given information.
Combined, SUFFICIENT.

Final Answer:
[Reveal] Spoiler:
C


GMAT assassins aren't born, they're made,
Rich
_________________

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests

60-point improvement guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Manager
Manager
User avatar
Joined: 15 Mar 2015
Posts: 105
Followers: 2

Kudos [?]: 20 [0], given: 7

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 16 May 2015, 08:34
B+C?

(1) B=1.5C. Clearly insufficient.

(2) 21<B+C<28

As we are working with integers, we can rule out 21 and 28. Thus: 22=<B+C=<27. This is still insufficient, though. As we still have 6 possibilities.

(1)+(2)
B+C should be divisible by 5/2. Because B+C = 2,5C and as we are working with countable items, we want to find an integer.

As such. We will have: Tot/(5/2)=Tot*2/5=2*tot/5 = integer.

To be divisible by 5, the number has to end in 5 or 0. For this reason I will only look at the unit digits. (2->7) 4,6,8,0,2,4. Only one out of the seven possibilities ended in 0 or 5, and thus only one possibility exists. C is sufficient.

(This looks as if it takes a lot of time, but it's not very time consuming when done in your head)
_________________

I love being wrong. An incorrect answer offers an extraordinary opportunity to improve.

Director
Director
User avatar
Joined: 10 Mar 2013
Posts: 608
Location: Germany
Concentration: Finance, Entrepreneurship
GMAT 1: 580 Q46 V24
GPA: 3.88
WE: Information Technology (Consulting)
Followers: 13

Kudos [?]: 247 [0], given: 200

GMAT ToolKit User
Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 31 May 2015, 02:43
B+C = ?
1) C + 1,5C = 2,5C Not sufficient
2) Clearly no sufficient. We need a relationship between B and C to make it work
1+2) 2,5C = 21-28
C = (21-28)*2/5, so we need a multiple of 5 --> 25*2 is the only mulstiple of 5 in the range 21 - 28
_________________

When you’re up, your friends know who you are. When you’re down, you know who your friends are.

Share some Kudos, if my posts help you. Thank you !

800Score ONLY QUANT CAT1 51, CAT2 50, CAT3 50
GMAT PREP 670
MGMAT CAT 630
KAPLAN CAT 660

Intern
Intern
avatar
Joined: 29 Jun 2015
Posts: 12
Concentration: Finance, Strategy
Schools: Kelley '19
GPA: 2.8
Followers: 0

Kudos [?]: 0 [0], given: 3

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 07 Jul 2015, 01:04
I tried the estimation strategy and I have 2 possible solutions that match the criterion. If they have 16 and 8 coins or they have 18 and 9 coins. Need help understanding the same.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 35843
Followers: 6830

Kudos [?]: 89752 [0], given: 10381

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 07 Jul 2015, 01:08
rushd25 wrote:
I tried the estimation strategy and I have 2 possible solutions that match the criterion. If they have 16 and 8 coins or they have 18 and 9 coins. Need help understanding the same.


It says that Bert has 50 percent more coins than Claire (B = 1.5C), not twice as many (B = 2C). Please refer to the solutions above.
_________________

New to the Math Forum?
Please read this: 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

Intern
Intern
avatar
Joined: 12 Jan 2016
Posts: 11
Followers: 0

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

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 08 Mar 2016, 18:35
fameatop wrote:
1) Let of no of coins with Claire = 2x
Let of no of coins with Bert = 3x
2x+3x = 5x --->x can take any value - Insufficient

2) No of coins can take any integer value from 21 to 28- Insufficient

1+2) Total no of coins must be a multiple of 5 & between 21 & 28. Only possible integer value is 25--->Sufficient
Answer C


I did this question the same way that fametop did, can anyone comment on if this is a good way to think about it. In terms of total coins needing to be a multiple of 5?
Expert Post
Math Forum Moderator
avatar
Joined: 20 Mar 2014
Posts: 2647
GMAT 1: 750 Q49 V44
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Followers: 113

Kudos [?]: 1307 [0], given: 786

GMAT ToolKit User Premium Member Reviews Badge
What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 08 Mar 2016, 18:50
grainflow wrote:
fameatop wrote:
1) Let of no of coins with Claire = 2x
Let of no of coins with Bert = 3x
2x+3x = 5x --->x can take any value - Insufficient

2) No of coins can take any integer value from 21 to 28- Insufficient

1+2) Total no of coins must be a multiple of 5 & between 21 & 28. Only possible integer value is 25--->Sufficient
Answer C


I did this question the same way that fametop did, can anyone comment on if this is a good way to think about it. In terms of total coins needing to be a multiple of 5?


Yes, this is a perfectly valid method for attacking this question.

Alternately, once you realize that B=1.5C and 21 < B+C < 28 ---> 21< 2.5C<28, remember that the total number of coins MUST be an integer.

Thus the final value must be a multiple of 2.5 ---> 25 is the ONLY value.

Hence C is the correct answer

Hope this helps.
_________________

Thursday with Ron updated list as of July 1st, 2015: http://gmatclub.com/forum/consolidated-thursday-with-ron-list-for-all-the-sections-201006.html#p1544515
Rules for Posting in Quant Forums: http://gmatclub.com/forum/rules-for-posting-please-read-this-before-posting-133935.html
Writing Mathematical Formulae in your posts: http://gmatclub.com/forum/rules-for-posting-please-read-this-before-posting-133935.html#p1096628
GMATCLUB Math Book: http://gmatclub.com/forum/gmat-math-book-in-downloadable-pdf-format-130609.html
Everything Related to Inequalities: http://gmatclub.com/forum/inequalities-made-easy-206653.html#p1582891
Inequalities tips: http://gmatclub.com/forum/inequalities-tips-and-hints-175001.html
Debrief, 650 to 750: http://gmatclub.com/forum/650-to-750-a-10-month-journey-to-the-score-203190.html

Intern
Intern
avatar
Joined: 12 Jan 2016
Posts: 11
Followers: 0

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

Re: What is the total number of coins that Bert and Claire have? [#permalink]

Show Tags

New post 08 Mar 2016, 18:57
Understood. This method just seemed so much easier than the other I wanted to make sure I was not overlooking something.
Re: What is the total number of coins that Bert and Claire have?   [#permalink] 08 Mar 2016, 18:57
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic If positive integer n<=3 and n is the number of times a coin is flippe Bunuel 1 11 Oct 2016, 01:15
1 Experts publish their posts in the topic What is the standard deviation of the values of the 20 coins in a Skywalker18 4 20 Jun 2016, 10:09
1 Experts publish their posts in the topic What is the total number of executives at Company P nalinnair 1 23 May 2016, 01:56
5 Experts publish their posts in the topic When a player in a certain game tossed a coin a number of Walkabout 3 14 Dec 2012, 07:28
9 Experts publish their posts in the topic When a player in a certain game tossed a coin a number of ti netcaesar 10 15 Jan 2008, 10:01
Display posts from previous: Sort by

What is the total number of coins that Bert and Claire have?

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


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.