vinay1983 wrote:Is x=y?
1. (x+y)* [1/x + 1/y] = 4
2. (x-50)^2 = (y-50)^2
Plug in a value for x and solve for y.
Statement 1: (x+y)* [1/x + 1/y] = 4
Case 1: x=1
(1+y) * (1/1 + 1/y) = 4
1 + 1/y + y/1 + 1 = 4
1/y + y/1 = 2.
Only y=1 will satisfy this equation.
In this case, x=y.
Case 2: x=5
(5+y) * (1/5 + 1/y) = 4
1 + 5/y + y/5 + 1 = 4
5/y + y/5 = 2.
Only y=5 will satisfy this equation.
In this case, x=y.
The implication of these two random cases is that -- regardless of the value of x -- x=y.
SUFFICIENT.
Statement 2: (x-50)² = (y-50)²
If x=51, we get:
(51-50)² = (y-50)²
1 = (y-50)²
y-50 = 1 or y-50 = -1
y=51 or y=49.
Since it's possible that x=y or that x≠y, INSUFFICIENT.
The correct answer is
A.
[spoiler][/spoiler]
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
