I have this question from GMAT Pretest - test 2
In the sequence of positive numbers x1, x2, x3,..., what is the value of x1?
1. xi = (xi-1)/2 for all integer i>1 (to clarify i.e x3=x2/2)
2. x5 = x4/(x4 + 1)
OA is C
Thanks for your help!
5-Day Free Trial
5-day free, full-access trial TTP
Available with Beat the GMAT members only code
MORE DETAILS
sequence number - expert pls help
This topic has expert replies
-
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
Neither statement alone is sufficient to determine the value of x�.VyDinh wrote:I have this question from GMAT Pretest - test 2
In the sequence of positive numbers x1, x2, x3,..., what is the value of x1?
1. xi = (xi-1)/2 for all integer i>1 (to clarify i.e x3=x2/2)
2. x5 = x4/(x4 + 1)
OA is C
Statements combined:
Statement 1 implies that xâ‚… = xâ‚„/2.
Statement 2 indicates that xâ‚… = xâ‚„/(xâ‚„ + 1).
Thus:
xâ‚„/2 = xâ‚„/(xâ‚„ + 1)
Since the numerators are equal, so must be the denominators:
2 = xâ‚„ + 1
xâ‚„ = 1.
Using the value of x₄, we can apply the formula in statement 1 to determine x₃, x₂, and x�.
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
