GMAT Question of the Day – Problem Solving – Exponents/Puzzle

Which of the following is equivalent to \( \frac{k-4}{\sqrt{k}-2} \)?

A. \( \sqrt{k} + 2 \)

B. k + 4

C. 4

D. 4k

E. 6k

Show the answer

Correct Answer: A.

GMAT Question of the Day Solution

On this GMAT question of the day it is important to recognize that the denominator is one half of a difference of squares (x + y)(x – y). In this case we have the “x – y” portion. You can go ahead and multiply top and bottom by the the other half (the “x + y” part) of the special quadratic in order to get rid of the root in the denominator. Once you’ve done that this question breaks down to some simple arithmetic. As always – take your time with your GMAT arithmetic. Speeding through it generally leads to mistakes which will slow you down.