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

 It is currently 21 Feb 2019, 16:07

### 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

## Events & Promotions

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar

February 21, 2019

February 21, 2019

10:00 PM PST

11:00 PM PST

Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.
• ### Free GMAT RC Webinar

February 23, 2019

February 23, 2019

07:00 AM PST

09:00 AM PST

Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT

# What is the value of (2x 5)^3 ?

Author Message
TAGS:

### Hide Tags

Intern
Joined: 08 Nov 2008
Posts: 38
What is the value of (2x 5)^3 ?  [#permalink]

### Show Tags

Updated on: 17 Dec 2017, 00:22
8
00:00

Difficulty:

25% (medium)

Question Stats:

71% (01:28) correct 29% (01:36) wrong based on 253 sessions

### HideShow timer Statistics

What is the value of $$(2x – 5)^3$$ ?

(1) $$(2x)^3 = 216$$

(2) $$(2x + 3)^2 = 81$$

Originally posted by gorden on 08 Nov 2008, 19:56.
Last edited by Bunuel on 17 Dec 2017, 00:22, edited 2 times in total.
Renamed the topic, edited the question, added the OA and moved to DS forum.
Manager
Joined: 30 Sep 2008
Posts: 111
Re: What is the value of (2x 5)^3 ?  [#permalink]

### Show Tags

08 Nov 2008, 20:06
1
1
(1) suff as (2x)^3 = 216 will return only 1 result of x
(2) insuff as (2x + 3)^2 = 81 will return 2 results

Ans: A
Board of Directors
Joined: 17 Jul 2014
Posts: 2587
Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
Re: What is the value of (2x 5)^3 ?  [#permalink]

### Show Tags

19 May 2016, 17:56
gorden wrote:
What is the value of (2x – 5)^3 ?

(1) (2x)^3 = 216
(2) (2x + 3)^2 = 81

1. sufficient. 2x = sqrt(216)
identify the prime factors of 216 = 2^3 * 3^3 -> 2x=2*3 => x=3. sufficient.

2. 2 outcomes:
2x+3=9 => 2x=6 => x=3
2x+3=-9 => 2x=-12 => x=-6

not sufficient.
Current Student
Status: DONE!
Joined: 05 Sep 2016
Posts: 373
Re: What is the value of (2x 5)^3 ?  [#permalink]

### Show Tags

18 Sep 2016, 08:19
A is correct. Here's why:

(1) 2x^3 = 216
= x^3 = 108 (if you do a 'tree', you'll see 108 factors down to 2,2,3,3,3) --> x = 3sqrt(2)

SUFFICIENT

(2) (2x+3)^2 = 81
=2x+3 = +/- 9

NOT SUFFICIENT
Non-Human User
Joined: 09 Sep 2013
Posts: 9879
Re: What is the value of (2x 5)^3 ?  [#permalink]

### Show Tags

16 Dec 2017, 16:14
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: What is the value of (2x 5)^3 ?   [#permalink] 16 Dec 2017, 16:14
Display posts from previous: Sort by