Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 24 May 2017, 21:28

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If Sara's age is exactly twice Bill's age, what is Sara's ag

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

### Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 178
Followers: 6

Kudos [?]: 2695 [1] , given: 0

If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

18 Dec 2012, 07:43
1
This post received
KUDOS
3
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

87% (01:49) correct 13% (00:55) wrong based on 569 sessions

### HideShow timer Statistics

If Sara's age is exactly twice Bill's age, what is Sara's age?

(1) Four years ago, Sara's age was exactly 3 times Bill's age.
(2) Eight years from now, Sara's age will be exactly 1.5 times Bill's age.
[Reveal] Spoiler: OA
Math Expert
Joined: 02 Sep 2009
Posts: 38859
Followers: 7728

Kudos [?]: 106061 [4] , given: 11607

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

18 Dec 2012, 07:47
4
This post received
KUDOS
Expert's post
3
This post was
BOOKMARKED
If Sara's age is exactly twice Bill's age, what is Sara's age?

Given: S = 2B.

(1) Four years ago, Sara's age was exactly 3 times Bill's age --> S - 4 = 3(B-4). We have two distinct linear equations (S - 4 = 3(B-4) and S = 2B) with two unknowns, thus we can solve for both. Sufficient.

(2) Eight years from now, Sara's age will be exactly 1.5 times Bill's age --> S + 8 =1.5(B + 8). The same here: we have two distinct linear equations with two unknowns, thus we can solve for both. Sufficient.

Answer: D.
_________________
Manager
Joined: 12 Dec 2012
Posts: 230
Concentration: Leadership, Marketing
GMAT 1: 540 Q36 V28
GMAT 2: 550 Q39 V27
GMAT 3: 620 Q42 V33
GPA: 2.82
WE: Human Resources (Health Care)
Followers: 4

Kudos [?]: 79 [1] , given: 181

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

19 Mar 2013, 14:00
1
This post received
KUDOS
I solved this correctly via solving simultaneous equations ... but I could not understand the other approach the OG mentioned in the answer explanation : " another way to conclude that we can determine the value of s is to note that the pair of equations represents 2 non - parallel lines in the coordinate plane"
_________________

My RC Recipe
http://gmatclub.com/forum/the-rc-recipe-149577.html

My Problem Takeaway Template
http://gmatclub.com/forum/the-simplest-problem-takeaway-template-150646.html

Intern
Joined: 28 Jan 2013
Posts: 1
Followers: 0

Kudos [?]: 5 [0], given: 21

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

06 Apr 2013, 04:48
TheNona wrote:
I solved this correctly via solving simultaneous equations ... but I could not understand the other approach the OG mentioned in the answer explanation : " another way to conclude that we can determine the value of s is to note that the pair of equations represents 2 non - parallel lines in the coordinate plane"

What they try to say is that the equations can be considered linear functions with different slopes. Therefore they will intersect at a certain point leading to one solution.
Manager
Joined: 12 Jan 2013
Posts: 220
Followers: 5

Kudos [?]: 72 [1] , given: 47

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

10 Jan 2014, 10:31
1
This post received
KUDOS
Walkabout wrote:
If Sara's age is exactly twice Bill's age, what is Sara's age?

(1) Four years ago, Sara's age was exactly 3 times Bill's age.
(2) Eight years from now, Sara's age will be exactly 1.5 times Bill's age.

We're given the equation S = 2B

1) S - 4 = 3(B - 4), we now have two equations and two unknowns, that's enough. Sufficient
2) S + 8 = 1.5(B + 8), again two equations and two unknowns, sufficient.

So, D.
Intern
Joined: 09 Feb 2014
Posts: 8
Followers: 0

Kudos [?]: 5 [0], given: 25

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

12 Oct 2014, 01:59
1
This post was
BOOKMARKED
I thought the answer would be A because

2) S=2B
and S+8 = 1.5(B+8); solve this we have B=4/3.5 => B is not an integer => insufficient

Should B and S be integers because they are years of age?
Could someone help to explain when integers should be considered and when not?
Math Expert
Joined: 02 Sep 2009
Posts: 38859
Followers: 7728

Kudos [?]: 106061 [1] , given: 11607

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

12 Oct 2014, 02:21
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
trambn wrote:
I thought the answer would be A because

2) S=2B
and S+8 = 1.5(B+8); solve this we have B=4/3.5 => B is not an integer => insufficient

Should B and S be integers because they are years of age?
Could someone help to explain when integers should be considered and when not?

When you solve S + 8 =1.5(B + 8) and S = 2B you get B = 8 and S = 16.

Also, why should a statement be insufficient if the result is not an integer?

And finally, I haven't seen a single official question where age is not an integer.

Check other Age Problems in our Speial Questions Directory.

Hope it helps
_________________
Intern
Joined: 10 Sep 2015
Posts: 18
Followers: 0

Kudos [?]: 1 [1] , given: 19

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

11 Sep 2015, 01:07
1
This post received
KUDOS
we have 1 equation as per given data

Statement 1 : gives another equation along with Given data , can be solved , sufficient
Statement 2 : gives another equation along with Given data , can be solved , sufficient

hence D
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 15431
Followers: 649

Kudos [?]: 207 [0], given: 0

Re: If Sara's age is exactly twice Bill's age, what is Sara's ag [#permalink]

### Show Tags

28 Sep 2016, 18:11
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.
_________________
Re: If Sara's age is exactly twice Bill's age, what is Sara's ag   [#permalink] 28 Sep 2016, 18:11
Similar topics Replies Last post
Similar
Topics:
If Harry's age is exactly three times Bill's age, what is Harry's age? 3 14 Apr 2017, 05:57
If Ron's age is exactly twice Will's age, what is Ron's age? 3 04 Apr 2017, 10:45
2 If Shannon's age is exactly half of Josh's age, what is Shannon's age? 4 17 Feb 2015, 04:01
4 What is Ricky's age now? 6 16 Aug 2016, 00:50
30 If Father's age is 1 less than twice the son's age, what is 11 24 Dec 2016, 07:16
Display posts from previous: Sort by

# If Sara's age is exactly twice Bill's age, what is Sara's ag

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

 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®.