It is currently 30 May 2020, 18:40

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# The functions f and g are defined as f(x, y) = 2x + y and g

Author Message
TAGS:
Founder
Joined: 18 Apr 2015
Posts: 11192
Followers: 239

Kudos [?]: 2808 [0], given: 10653

The functions f and g are defined as f(x, y) = 2x + y and g [#permalink]  14 May 2019, 01:12
Expert's post
00:00

Question Stats:

91% (00:28) correct 8% (00:44) wrong based on 12 sessions
The functions f and g are defined as f(x, y) = 2x + y and g(x, y) = x + 2y.

 Quantity A Quantity B f(3, 4) + g(3, 4) f(4, 3) + g(4, 3)

A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
[Reveal] Spoiler: OA

_________________

Need Practice? 20 Free GRE Quant Tests available for free with 20 Kudos
GRE Prep Club Members of the Month: Each member of the month will get three months free access of GRE Prep Club tests.

GRE Prep Club Tests Editor
Affiliations: Partner at MyGuru LLC.
Joined: 13 May 2019
Posts: 151
Location: United States
GMAT 1: 770 Q51 V44
GRE 1: Q169 V168
WE: Education (Education)
Followers: 6

Kudos [?]: 150 [0], given: 2

Re: The functions f and g are defined as f(x, y) = 2x + y and g [#permalink]  14 May 2019, 08:15
Expert's post
When provided algebra for Quantitative Comparison problems, consider solving algebraically first, because the approach is likely to be more efficient than plugging in.

In this case we have:

 Quantity A Quantity B f(3, 4) + g(3, 4) f(4, 3) + g(4, 3)

Now, in the root statement f(x, y) = 2x + y and g(x + y) = x + 2y | Since both quantities sum these equations, stack and sum the full equations to efficiently compare the quantities.

2x + y
+ x + 2y
3x + 3y

Without plugging in, it can be determined that when adding the two functions of both quantities the x and y coefficients will remain equal. Therefore, since the x and y values are the same in both quantities, the quantities themselves will always be equal, which is choice C.
_________________

Stefan Maisnier

Re: The functions f and g are defined as f(x, y) = 2x + y and g   [#permalink] 14 May 2019, 08:15
Display posts from previous: Sort by