Hello,
Can you please assist with this:
Some computers at a certain company are Brand X and the rest are Brand Y. If the ratio of the number of Brand Y computers to the number of Brand X computers at the company is 5 to 6, how many of the computers are Brand Y?
(1) There are 80 more brand X computers than Brand Y computers at the company
(2) There is a total of 880 computers at the company
OA: D
I was not clear with the approach explained in the OG.
Thanks for your help.
Best Regards,
Sri
Ratio problem?
This topic has expert replies
-
- Legendary Member
- Posts: 641
- Joined: Tue Feb 14, 2012 3:52 pm
- Thanked: 11 times
- Followed by:8 members
-
- Master | Next Rank: 500 Posts
- Posts: 423
- Joined: Fri Jun 11, 2010 7:59 am
- Location: Seattle, WA
- Thanked: 86 times
- Followed by:2 members
Lets Brand X computers be 6x
Lets Brand Y computers be 5x
Total compueters = 11x
St1: 6x - 5x = 80 or x = 80
# of Brand Y computers = 80 * 5 = 400
Sufficient
St2: 11x = 880 or x = 80
# of Brand Y computers = 80 * 5 = 400
Sufficient
Hence D
Lets Brand Y computers be 5x
Total compueters = 11x
St1: 6x - 5x = 80 or x = 80
# of Brand Y computers = 80 * 5 = 400
Sufficient
St2: 11x = 880 or x = 80
# of Brand Y computers = 80 * 5 = 400
Sufficient
Hence D
- GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Question stem:gmattesttaker2 wrote:Hello,
Can you please assist with this:
Some computers at a certain company are Brand X and the rest are Brand Y. If the ratio of the number of Brand Y computers to the number of Brand X computers at the company is 5 to 6, how many of the computers are Brand Y?
(1) There are 80 more brand X computers than Brand Y computers at the company
(2) There are a total of 880 computers at the company
OA: D
y/x = 5/6
5x = 6y.
Statement 1: There are 80 more brand X computers than Brand Y computers at the company.
x = y + 80.
Since we have two variables and two distinct linear equations (5x=6y and x=y+80), we can solve for each variable.
SUFFICIENT.
Statement 2: There are a total of 880 computers at the company.
x+y = 880.
Since we have two variables and two distinct linear equations (5x=6y and x+y=880), we can solve for each variable.
SUFFICIENT.
The correct answer is D.
A quick way to solve for x and y that requires little algebra:
y/x = 5/6.
If x=6 and y=5, then x-y = 1.
Statement 1 indicates that x-y = 80.
To yield a difference 80 TIMES AS GREAT as x-y=1, x and y must each be multiplied by a FACTOR OF 80:
x = 6*80 = 480.
y = 5*80 = 400.
These values satisfy both statements:
x-y = 80.
x+y = 880.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
GMAT/MBA Expert
- Scott@TargetTestPrep
- GMAT Instructor
- Posts: 7247
- Joined: Sat Apr 25, 2015 10:56 am
- Location: Los Angeles, CA
- Thanked: 43 times
- Followed by:29 members
Solution:gmattesttaker2 wrote: ↑Tue May 28, 2013 10:13 pm
Some computers at a certain company are Brand X and the rest are Brand Y. If the ratio of the number of Brand Y computers to the number of Brand X computers at the company is 5 to 6, how many of the computers are Brand Y?
(1) There are 80 more brand X computers than Brand Y computers at the company
(2) There is a total of 880 computers at the company
OA: D
Question Stem Analysis:
We need to determine the number of Brand Y computers at a certain company, given that the ratio of the number of brand Y computers to the number of Brand X computers at the company is 5 to 6. That is, if let the number of Brand Y computers be y, then the number of Brand X computers is 6y / 5 (notice that y / (6y/5) = 5/6). We need to determine the value of y.
Statement One Alone:
We can create the equation:
y + 80 = 6y/5
80 = y/5
400 = y
Statement one alone is sufficient.
Statement Two Alone:
We can create the equation:
y + 6y/5 = 880
11y/5 = 880
y/5 = 80
y = 400
Statement two alone is sufficient
Answer: D
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews