I believe the problem should read as follows:
If k and x are positive integers and x is divisible by 6, which of the following CANNOT be the value of √(288kx)?
A.24k√3
B.24√k
C.24√3k
D.24√6k
E.72√k
√(288kx) = √(2*144*kx) = 12√(2kx).
Set the answer choices equal to 12√(2kx).
The correct answer choice will yield an equation that is NOT viable.
Answer choice A:
24k√3 = 12√(2kx)
2k√3 = √(2kx)
[2k√3]² = [√(2kx)]²
4 * k² * 3 = 2kx
6k = x.
This works.
If k=1, then x=6, satisfying the constraint that x must be divisible by 6.
Eliminate A.
Answer choice B:
24√k = 12√(2kx)
2√k = √(2kx)
[2√k]² = [√(2kx)]²
4k = 2kx
2 = x.
Doesn't work: x must be a multiple of 6.
The correct answer is
B.
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
