my brain hurts after this one!

[dux3000]

k < 0

Quantity A: (2k - 5)(k - 1)/(k^2 - k) 

Quantity B: 2

Worse yet, they say this is a medium question? Is it?

Here's their solution http://www.greenlighttestprep.com/module/gre-algebra-and-equation-solving/video/962

Is there an easier way? I never would have gotten this. 

[TakeruK]

I think the video's method is the easiest way. The overall lesson to be learned from this type of question, in my opinion, is when you have a big mess like Quantity A, and you have to compare it to something simple like in B, you always need to simplify the big mess and relate it to the value in B in some way. 

The other mathematical rule you should remember is that (a-b)/c = a/c - b/c (same goes for a + sign too). This rule was useful in the other question you posted today too.

[dux3000]

Thanks again TakeruK. 

I was hoping there was a quick trick to avoid all of that work. Wishful thinking!

 

[GREMasterEMPOWERRichC]

k < 0

Quantity A: (2k - 5)(k - 1)/(k^2 - k) 

Quantity B: 2

Worse yet, they say this is a medium question? Is it?

Here's their solution http://www.greenlighttestprep.com/module/gre-algebra-and-equation-solving/video/962

Is there an easier way? I never would have gotten this. 

Hi dux3000,

Although it won't be too common on Test Day, certain QCs are going to be more complex (and require more work from you) than others will, so you should be ready to spend that time doing work (NOT staring) to get to the correct answer.

We're told that K is NEGATIVE. The real work in this question is in Quantity A, but it's really just basic arithmetic, so let's TEST VALUES and see if a pattern emerges...

IF.... K = -1, then...

A = (-7)(-2)/(1 - -1) = 14/2 = 7

Quantity A is greater

IF.... K = -2, then...

A = (-9)(-3)/(4 - -2) = 27/6 = 4.5

Quantity A is greater

IF.... K = -10, then...

A = (-25)(-11)/(100 - -11) = 275/111 = MORE than 2

Quantity A is greater

It certainly appears that Quantity A is always going to be greater, so the Final Answer is A.

GRE Masters aren't born, they're made,

Rich

[dux3000]

I know about that strategy but I worry that I don't test the right numbers. 

Thanks though. 

[GREMasterEMPOWERRichC]

Hi dux3000,

TESTing VALUES is a remarkably useful tactic in the Quant section, so it's a skill that's worth practicing. Most Test Takers are not 'born' with that specific skill, much in the same way that they are not born with a huge 'GRE vocabulary', but they can both be developed. You just have to put in the necessary time and effort.

GRE Masters aren't born, they're made,

Rich