Find all School-related info fast with the new School-Specific MBA Forum

It is currently 04 Aug 2015, 02:09
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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If the ratio x: y:z is 3:5:7, what is the value of z

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 24 Nov 2012
Posts: 25
Followers: 0

Kudos [?]: 17 [0], given: 0

If the ratio x: y:z is 3:5:7, what is the value of z [#permalink] New post 29 Nov 2012, 08:56
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

88% (01:37) correct 12% (00:51) wrong based on 49 sessions
If the ratio x: y:z is 3:5:7, what is the value of z?

(1) The average (arithmetic mean) of x, y, and z is 25.
(2) The value of x is 15.
[Reveal] Spoiler: OA

Last edited by Bunuel on 19 Mar 2015, 04:38, edited 2 times in total.
Edited the tags.
BSchool Thread Master
User avatar
Status: Tutor
Joined: 05 Apr 2011
Posts: 518
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 570 Q49 V19
GMAT 2: 700 Q51 V31
GPA: 3
WE: Information Technology (Computer Software)
Followers: 72

Kudos [?]: 378 [0], given: 47

Premium Member
Re: If the ratio x: y:z is 3:5:7, what is the value of z [#permalink] New post 29 Nov 2012, 09:01
ritumaheshwari02 wrote:
If the ratio x: y:z is 3:5:7, what is the value of z?

(1) The average (arithmetic mean) of x, y, and z is 25.
(2) The value of x is 15.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

OFFICIAL ANSWER IS NOT PROVIDED.


x:y:z = 3:5:7
means x=3k, y=5k, z=7k where k is the common value in all the three numbers.

STAT1
(x+y+z)/3 = 25
x+y+z = 75
=> 3k + 5k+ 7k = 75
15k = 75
k = 5
z = 7k = 35
SUFFICIENT

STAT2
x= 15
=> 3k = 15
=> k =5
=> z = 7k = 7*5 = 35
SUFFICIENT

Answer will be D
Hope it helps!
_________________

Ankit
You must Believe

GMAT Quant Tutor
How to start GMAT preparations?
How to Improve Quant Score?
Gmatclub Topic Tags
Check out my GMAT debrief

Quant Formula Sheet

How to Solve :
Statistics || Reflection of a line || Remainder Problems || Inequalities

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5728
Followers: 324

Kudos [?]: 64 [0], given: 0

Premium Member
Re: If the ratio x: y:z is 3:5:7, what is the value of z [#permalink] New post 17 Mar 2015, 05:06
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
EMPOWERgmat Instructor
User avatar
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 3102
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 133

Kudos [?]: 856 [0], given: 54

Re: If the ratio x: y:z is 3:5:7, what is the value of z [#permalink] New post 18 Mar 2015, 19:04
Expert's post
Hi All,

With the given ratio, we know that X is a multiple of 3, Y is an equivalent multiple of 5 and Z is an equivalent multiple of 7. By extension, the sum of those 3 terms is a multiple of 15

For example, we could have X=3, Y=5 and Z=7 (and the sum = 15) or X=6, Y=10, Z=14 (and the sum = 30)

We're asked for the value of Z .

Fact 1: The average (arithmetic mean) of x, y, and z is 25.

Since the average of the 3 terms is 25, the SUM of the three terms is 75.

75 is a 5 times 15, so we can calculate the value of all 3 variables:

X = 3(5) = 15
Y = 5(5) = 25
Z = 7(5) = 35
Fact 1 is SUFFICIENT

Fact 2: The value of x is 15.

Since X = 15, we can figure out the "multiple of 3" that we're dealing with. 3(5) = 15, so we have to multiply the Y and the Z by 5 also.

Y = 5(5) = 25
Z = 7(5) = 35
Fact 2 is SUFFICIENT

Final Answer:
[Reveal] Spoiler:
D


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

Official Guide 2016 Question Breakdown:
http://gmatclub.com/forum/empowergmat-blog-198415.html#p1527977

Rich Cohen
Rich.C@empowergmat.com
http://www.empowergmat.com

GMAT Club Verified Reviews for EMPOWERgmat & Special Discount

EMPOWERgmat Podcast - A Wild Secret About The GMAT Algorithm


Re: If the ratio x: y:z is 3:5:7, what is the value of z   [#permalink] 18 Mar 2015, 19:04
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic If 2x = 2y – 3z, what is the value of z? Bunuel 6 14 Apr 2015, 03:52
12 Experts publish their posts in the topic What is the ratio x : y: z ? Ric123 7 09 Jan 2014, 20:57
4 Is (2^(y+z))(3^x)(5^y)(7^z) < (90^y)(14^z) amgelcer 3 28 Sep 2013, 07:59
2 If 3x – 3y = 12z, what is the value of x manalq8 7 19 Nov 2011, 11:24
8 Experts publish their posts in the topic What is the ratio of x:y:z? lumone 10 27 Nov 2007, 07:17
Display posts from previous: Sort by

If the ratio x: y:z is 3:5:7, what is the value of z

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| 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®.