Post your question in the Comment section below, and a GRE expert will answer it as fast as humanly possible.

- Video Course
- Video Course Overview
- General GRE Info and Strategies - 7 videos (free)
- Quantitative Comparison - 7 videos (free)
- Arithmetic - 42 videos
- Powers and Roots - 43 videos
- Algebra and Equation Solving - 78 videos
- Word Problems - 54 videos
- Geometry - 48 videos
- Integer Properties - 34 videos
- Statistics - 28 videos
- Counting - 27 videos
- Probability - 25 videos
- Data Interpretation - 24 videos
- Analytical Writing - 9 videos (free)
- Sentence Equivalence - 39 videos (free)
- Text Completion - 51 videos
- Reading Comprehension - 16 videos

- Study Guide
- Philosophy
- Office Hours
- Extras
- Prices

## Comment on

k's on Both Sides## This is definitely a quicker

## Your method is great (however

Your method is great (however, when you replaced k with 1, you should have found that the two quantities are equal). In fact, the strategy you used is covered in this video: https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi...

The strategy I used is called Matching Operations. It's covered here: https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi...

## my way was to plug some

## That works too! Just keep in

That works too! Just keep in mind that plugging in numbers only yields a conclusive result when the answer is D. For more see https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi... (starting at 2:50)

## So in a question like this

## Those are the steps I took

Those are the steps I took for this question, but I would advise against memorizing steps. Just follow the basic guidelines/rules that we cover in this related video: https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi...

Notice that I could have taken a different route (while still adhering to the rules of Matching Operations (as covered in the above video). For example...

QUANTITY A: 3k + 5

QUANTITY B: 11 - 3k

Subtract 5 from both quantities to get:

QUANTITY A: 3k

QUANTITY B: 6 - 3k

Add 3k to both quantities to get:

QUANTITY A: 6k

QUANTITY B: 6

Divide both quantities by 6 to get:

QUANTITY A: k

QUANTITY B: 1

Answer: D

## Hello! I dont understand the

## Hi Dsho,

Hi Dsho,

Here, the two quantities are expressions.

So, Quantity A and Quantity B can have a variety of values, depending on the value of k.

Regarding the technique used to answer the question, this video covers everything you need to know: https://www.greenlighttestprep.com/module/gre-quantitative-comparison/vi...

Please let me know if that helps.

Cheers,

Brent

## Hi!

I have a question.

I approach this question by squaring both sides, so I could exclude K and get only positive integers. Why was my solution wrong?

## That strategy can get you

That strategy can get you into trouble, because squaring a NEGATIVE will turn that number into a POSITIVE number.

Consider this example:

QUANTITY A: 2

QUANTITY B: -3

We can clearly see that Quantity A is bigger

However, if we SQUARE both quantities, we get:

QUANTITY A: 4

QUANTITY B: 9

Now Quantity B is bigger

Also, keep in mind that we're already told that k is positive (k > 0)

Cheers,

Brent

## First check for equal case -

Assume they are equal => 3k+5 = 11-3k

Simplify, get k=1 so when K is 1 both quantities are equal.

At this point we know that we met the equal case,

Now, check for inequality case => plug k=2 in both the quantities.

3(2)+5 11-3(2)

11 11-6 ----> here clearly A is greater.

As such we have 2 answers. The right answer is D

## Perfectly valid approach -

Perfectly valid approach - nice work!