Last visit was: 18 Nov 2024, 14:44 It is currently 18 Nov 2024, 14:44

Close

GRE Prep 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
Your Progress

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

Practice
Pays

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Verbal Expert
Joined: 18 Apr 2015
Posts: 29976
Own Kudos [?]: 36273 [2]
Given Kudos: 25915
Send PM
GRE Prep Club Tests Editor
Joined: 13 May 2019
Affiliations: Partner at MyGuru LLC.
Posts: 186
Own Kudos [?]: 332 [0]
Given Kudos: 5
Location: United States
GMAT 1: 770 Q51 V44
GRE 1: Q169 V168
WE:Education (Education)
Send PM
avatar
Manager
Manager
Joined: 22 May 2019
Posts: 58
Own Kudos [?]: 51 [0]
Given Kudos: 0
Send PM
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Own Kudos [?]: 12192 [0]
Given Kudos: 136
Send PM
Re: A function f(x) is defined for all real numbers as f(x) = (x [#permalink]
2
Carcass wrote:
A function f(x) is defined for all real numbers as f(x) = (x – 1)(x – 2)(x – 3)(x – 4)


Quantity A
Quantity B
f(2.5)
f(3.5)


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.


Quantity A: f(2.5) = (2.5 – 1)(2.5 – 2)(2.5 – 3)(2.5 – 4)
= (1.5)(0.5)(-0.5)(-1.5)
= (POSITIVE)(POSITIVE)(NEGATIVE)(NEGATIVE)
= (POSITIVE)(POSITIVE)(POSITIVE)
= POSITIVE

Quantity B: f(3.5) = (3.5 – 1)(3.5 – 2)(3.5 – 3)(3.5 – 4)
= (2.5)(1.5)(0.5)(-0.5)
= (POSITIVE)(POSITIVE)(POSITIVE)(NEGATIVE)
= (POSITIVE)(NEGATIVE)
= NEGATIVE

Answer: A

Cheers,
Brent
Moderator
Moderator
Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1111
Own Kudos [?]: 963 [1]
Given Kudos: 9
Location: India
Concentration: General Management
Schools: XLRI Jamshedpur, India - Class of 2014
GMAT 1: 700 Q51 V31
GPA: 2.8
WE:Engineering (Computer Software)
Send PM
Re: A function f(x) is defined for all real numbers as f(x) = (x [#permalink]
1
Given that f(x) = (x – 1)(x – 2)(x – 3)(x – 4)

Quantity A = f(2.5)

To find f(2.5) we need to substitute x=2.5 in f(x) = (x – 1)(x – 2)(x – 3)(x – 4)
=> f(2.5) = (x – 1)(x – 2)(x – 3)(x – 4) = (2.5 – 1)(2.5 – 2)(2.5 – 3)(2.5 – 4) = 1.5 * 0.5 * -0.5 * -1.5 = 2.25 * 0.25 = 0.5625

Quantity B = f(3.5)

To find f(2.5) we need to substitute x=2.5 in f(x) = (x – 1)(x – 2)(x – 3)(x – 4)
=> f(2.5) = (x – 1)(x – 2)(x – 3)(x – 4) = (3.5 – 1)(3.5 – 2)(3.5 – 3)(3.5 – 4) = 2.5 * 1.5 * 0.5 * -0.5
We can directly stop here as this value is coming negative, but solving to complete the solution
= -0.9375

Clearly Quantity A > Quantity B

So, Answer will be A
Hope it helps!

Watch the following video to learn the Basics of Functions and Custom Characters

Prep Club for GRE Bot
Re: A function f(x) is defined for all real numbers as f(x) = (x [#permalink]
Moderators:
GRE Instructor
78 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne