GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Aug 2018, 06:06

### 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

# If 2(x – 1)^3 + 3 >= 19, which of the following must be true?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 47967
If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

23 Jul 2018, 20:35
00:00

Difficulty:

15% (low)

Question Stats:

89% (01:03) correct 11% (01:20) wrong based on 36 sessions

### HideShow timer Statistics

If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

(A) $$x \leq 3$$

(B) $$x \geq 3$$

(C) $$x \leq - 3$$

(D) $$x \geq - 3$$

(E) $$x < - 3$$ or $$x > 3$$

_________________
Manager
Joined: 17 Jan 2017
Posts: 137
Location: India
GPA: 4
WE: Information Technology (Computer Software)
If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

Updated on: 23 Jul 2018, 21:20
Bunuel wrote:
If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

(A) $$x \leq 3$$

(B) $$x \geq 3$$

(C) $$x \leq - 3$$

(D) $$x \geq - 3$$

(E) $$x < - 3$$ or $$x > 3$$

Just substitute values in the equation.

If x = 1 - Doesn't satisfy
x = -1 - Doesn't satisfy
x = 2 - Doesn't satisfy
x = -2 - Doesn't satisfy
x = 3 - Satisfies
x = -3 - Doesn't satisfy

So when x is greater than or equal to 3 equation satisfies, From options B
_________________

Correct me If I'm wrong !! looking for valuable inputs

KUDOS please, if you like the post or if it helps !!

Originally posted by Akash720 on 23 Jul 2018, 20:55.
Last edited by Akash720 on 23 Jul 2018, 21:20, edited 2 times in total.
RC Moderator
Status: Perfecting myself for GMAT
Joined: 22 May 2017
Posts: 432
Concentration: Nonprofit
Schools: Haas '21
GPA: 4
WE: Engineering (Computer Software)
Re: If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

23 Jul 2018, 21:16
2
Bunuel wrote:
If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

$$2(x – 1)^3 + 3 \geq 19$$

=> $$2(x – 1)^3 \geq 16$$

=> $$(x – 1)^3 \geq 8$$

=> $$(x – 1)^3 \geq 2^3$$

=> $$x-1 \geq 2$$

=> $$x \geq 3$$

Hence option B
_________________

If you like my post press kudos +1

New - RC Butler - 2 RC's everyday

Tag me in RC questions if you need help. Please provide your analysis of the question in the post along with the tag.

Senior Manager
Joined: 31 Oct 2013
Posts: 477
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

Updated on: 23 Jul 2018, 21:32
Bunuel wrote:
If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

(A) $$x \leq 3$$

(B) $$x \geq 3$$

(C) $$x \leq - 3$$

(D) $$x \geq - 3$$

(E) $$x < - 3$$ or $$x > 3$$

Given

$$2(x – 1)^3 + 3 \geq 19$$

$$2(x-1)^3 >= 16$$

$$(x-1)^3 >= 8$$

$$(x-1)^3 >= 2^3$$

x-1 >= 2

x>=3

Thus the best answer is B.

Originally posted by selim on 23 Jul 2018, 21:17.
Last edited by selim on 23 Jul 2018, 21:32, edited 2 times in total.
Senior Manager
Joined: 31 Oct 2013
Posts: 477
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

23 Jul 2018, 21:19
Akash720 wrote:
Bunuel wrote:
If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

(A) $$x \leq 3$$

(B) $$x \geq 3$$

(C) $$x \leq - 3$$

(D) $$x \geq - 3$$

(E) $$x < - 3$$ or $$x > 3$$

Just substitute values in the equation.

If x = 1 - Doesn't satisfy
x = -1 - Satisfies
x = 2 - Doesn't satisfy
x = -2 - Satisfies
x = 3 - Satisfies
x = -3 - Satisfies

So when x < -1 and x > 3 equation satisfies, From options E

As the exponent is odd , x can't be negative. Otherwise , negative value can't be greater than 8 or 16. Thanks.
Manager
Joined: 17 Jan 2017
Posts: 137
Location: India
GPA: 4
WE: Information Technology (Computer Software)
Re: If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

23 Jul 2018, 21:22
selim wrote:
Akash720 wrote:
Bunuel wrote:
If $$2(x – 1)^3 + 3 \geq 19$$, which of the following must be true?

(A) $$x \leq 3$$

(B) $$x \geq 3$$

(C) $$x \leq - 3$$

(D) $$x \geq - 3$$

(E) $$x < - 3$$ or $$x > 3$$

Just substitute values in the equation.

If x = 1 - Doesn't satisfy
x = -1 - Satisfies
x = 2 - Doesn't satisfy
x = -2 - Satisfies
x = 3 - Satisfies
x = -3 - Satisfies

So when x < -1 and x > 3 equation satisfies, From options E

As the exponent is odd , x can't be negative. Otherwise , negative value can't be greater than 8 or 16. Thanks.

Thanks for pointing out selim careless mistake from my side
_________________

Correct me If I'm wrong !! looking for valuable inputs

KUDOS please, if you like the post or if it helps !!

Intern
Joined: 02 May 2015
Posts: 26
Location: United States (NJ)
Schools: Wharton Exec '19
GMAT 1: 720 Q48 V41
GPA: 3.4
Re: If 2(x – 1)^3 + 3 >= 19, which of the following must be true?  [#permalink]

### Show Tags

23 Jul 2018, 21:50
B it is !

If 2(x – 1)^3 + 3 >= 19

when you solve through the inequalities you get

(x-1)^3 >= 8

x >= 3
Re: If 2(x – 1)^3 + 3 >= 19, which of the following must be true? &nbs [#permalink] 23 Jul 2018, 21:50
Display posts from previous: Sort by

# Events & Promotions

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.