What is the value of y?
(1) 3|x2 - 4| = y - 2
(2) |3 - y| = 11
MGMAT CAT 3
This topic has expert replies
- Stendulkar
- Junior | Next Rank: 30 Posts
- Posts: 26
- Joined: Wed Dec 22, 2010 12:53 am
- Thanked: 1 times
-
- Master | Next Rank: 500 Posts
- Posts: 161
- Joined: Mon Apr 05, 2010 9:06 am
- Location: Mumbai
- Thanked: 37 times
Hi,
Statement 1:
If x = 1, y = 11
If x = 2, y = 8
(I am assuming x2 stands for x^2)
We are getting different values of y - depending on the value of x. Hence, insuff
Statement 2:
3 - y = -11 or 11
y = 14 or -8
We are getting different values of y. Hence, insuff.
Combining both 1 & 2:
If y = -8,
3|x2 - 4| = -10
|x2 - 4| = -10/3 -> a negative number which is NOT a possibility
If y = 14,
3|x2 - 4| = 12
|x2 - 4| = 4
x2 - 4 = -4 or +4
x2 = 0 or 8
x = 0, -2root(2) or +2root(2).
There may be three values of x - however, all of them lead to only one value of y; which is 14. Hence, suff. Is it C ???
Thanks. Hope this helps.
Statement 1:
If x = 1, y = 11
If x = 2, y = 8
(I am assuming x2 stands for x^2)
We are getting different values of y - depending on the value of x. Hence, insuff
Statement 2:
3 - y = -11 or 11
y = 14 or -8
We are getting different values of y. Hence, insuff.
Combining both 1 & 2:
If y = -8,
3|x2 - 4| = -10
|x2 - 4| = -10/3 -> a negative number which is NOT a possibility
If y = 14,
3|x2 - 4| = 12
|x2 - 4| = 4
x2 - 4 = -4 or +4
x2 = 0 or 8
x = 0, -2root(2) or +2root(2).
There may be three values of x - however, all of them lead to only one value of y; which is 14. Hence, suff. Is it C ???
Thanks. Hope this helps.
Naveenan Ramachandran
4GMAT, Dadar(W) & Ghatkopar(W), Mumbai
4GMAT, Dadar(W) & Ghatkopar(W), Mumbai
- 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
Statement 1: 3|x² - 4| = y - 2.What is the value of y?
(1) 3|x2 - 4| = y - 2
(2) |3 - y| = 11
If x=0, then y=14.
If x=2, then y=2.
Since y can be different values, insufficient.
Statement 2: |3 - y| = 11.
Solving 3-y = 11 and 3-y = -11, we get:
y = -8 or y=14.
Since both y = -8 and y=14 are possible, insufficient.
Statements 1 and 2 combined:
Statement 2 requires that y = -8 or y=14.
Plugging y = -8 into 3|x² - 4| = y - 2, we get:
3|x² - 4| = -8-2
3|x² - 4| = -10
Not possible, since the left side cannot yield a negative result.
Thus, y=14.
Sufficient.
The correct answer is C.
Last edited by GMATGuruNY on Fri Oct 02, 2015 10:48 am, edited 1 time in total.
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
-
- Master | Next Rank: 500 Posts
- Posts: 222
- Joined: Mon Oct 13, 2008 4:04 pm
- Thanked: 3 times
- Followed by:2 members
Hello-
For statement 1 what is the assumption that you had made to take as 0 in the first instance
I could have taken 1 or 10 why 0
that does get you to thr right solution but why 0?
Thanks
For statement 1 what is the assumption that you had made to take as 0 in the first instance
I could have taken 1 or 10 why 0
that does get you to thr right solution but why 0?
Thanks
GMATGuruNY wrote:Statement 1: 3|x^2 - 4| = y - 2.Stendulkar wrote:What is the value of y?
(1) 3|x2 - 4| = y - 2
(2) |3 - y| = 11
If x=0, y=14.
If x=2, y=2.
Since both y=14 and y=2 are possible, insufficient.
Statement 2: |3 - y| = 11.
Solving 3-y = 11 and 3-y = -11, we get:
y= -8 or y=14.
Since both y= -8 and y=14 are possible, insufficient.
Statements 1 and 2 combined:
Statement 2 requires that y= -8 or y=14.
Plugging y= -8 into 3|x^2 - 4| = y - 2, we get:
3|x^2 - 4| = -8-2
3|x^2 - 4| = -10
Not possible, since the left side cannot yield a negative result.
Thus, y=14.
Sufficient.
The correct answer is C.
- 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
When we evaluate statement 1, we could plug in any value for x; I just happened to choose x=0 and x=2. The point is that since x can be more than value, y can be more than one value. Thus, statement 1 is insufficient.venmic wrote:Hello-
For statement 1 what is the assumption that you had made to take as 0 in the first instance
I could have taken 1 or 10 why 0
that does get you to thr right solution but why 0?
Thanks
GMATGuruNY wrote:Statement 1: 3|x^2 - 4| = y - 2.Stendulkar wrote:What is the value of y?
(1) 3|x2 - 4| = y - 2
(2) |3 - y| = 11
If x=0, y=14.
If x=2, y=2.
Since both y=14 and y=2 are possible, insufficient.
Statement 2: |3 - y| = 11.
Solving 3-y = 11 and 3-y = -11, we get:
y= -8 or y=14.
Since both y= -8 and y=14 are possible, insufficient.
Statements 1 and 2 combined:
Statement 2 requires that y= -8 or y=14.
Plugging y= -8 into 3|x^2 - 4| = y - 2, we get:
3|x^2 - 4| = -8-2
3|x^2 - 4| = -10
Not possible, since the left side cannot yield a negative result.
Thus, y=14.
Sufficient.
The correct answer is C.
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