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

 It is currently 21 Feb 2019, 08:51

### 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

# 21, 17, 9, 12, x, 5, 0, y What is the value of x in the list above?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 53063
21, 17, 9, 12, x, 5, 0, y What is the value of x in the list above?  [#permalink]

### Show Tags

31 Jan 2019, 00:28
00:00

Difficulty:

25% (medium)

Question Stats:

91% (00:56) correct 9% (01:42) wrong based on 14 sessions

### HideShow timer Statistics

21, 17, 9, 12, x, 5, 0, y

What is the value of x in the list above?

(1) y = x − 4

(2) The arithmetic mean of the numbers in the list is 10.

_________________
VP
Joined: 31 Oct 2013
Posts: 1159
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: 21, 17, 9, 12, x, 5, 0, y What is the value of x in the list above?  [#permalink]

### Show Tags

31 Jan 2019, 00:53
Bunuel wrote:
21, 17, 9, 12, x, 5, 0, y

What is the value of x in the list above?

(1) y = x − 4

(2) The arithmetic mean of the numbers in the list is 10.

we are asked to find out the value of x.

Statement 1: y = x -4.

21 + 17 + 9 +12 + x +5 + 0 +y

21 + 17 + 9 + 12 + x + 5 + 0 + x - 4

Still it's impossible to find out the value of x as we don't know the total.

Statement 2; average is given. Not sufficient. we have 2 variables in the stem .

Combining : Sufficient. Statement 1 helps us reduce the number of variables and statement 2 gives us total.

21 + 17 + 9 + 12 + x + 5 + 0 + x - 4 = 10*8

2x + 60 = 80

2x = 20

x = 10.

SVP
Joined: 18 Aug 2017
Posts: 1909
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: 21, 17, 9, 12, x, 5, 0, y What is the value of x in the list above?  [#permalink]

### Show Tags

31 Jan 2019, 02:26
Bunuel wrote:
21, 17, 9, 12, x, 5, 0, y

What is the value of x in the list above?

(1) y = x − 4

(2) The arithmetic mean of the numbers in the list is 10.

#1
value of x & y not know in sufficient
#2
mean = 10
so x+y = 10 * 8 - 64
x+y=16
not sufficient
1& 2
combine
2x=20
x= 10
sufficient
IMO C
_________________

If you liked my solution then please give Kudos. Kudos encourage active discussions.

Re: 21, 17, 9, 12, x, 5, 0, y What is the value of x in the list above?   [#permalink] 31 Jan 2019, 02:26
Display posts from previous: Sort by