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

 It is currently 18 Oct 2019, 04:51

### 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

# What is the average (arithmetic mean) of (√8 + √2)^2 and (√8 − √2)^2 ?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58458
What is the average (arithmetic mean) of (√8 + √2)^2 and (√8 − √2)^2 ?  [#permalink]

### Show Tags

17 Oct 2018, 02:23
00:00

Difficulty:

15% (low)

Question Stats:

88% (01:01) correct 12% (01:29) wrong based on 50 sessions

### HideShow timer Statistics

What is the average (arithmetic mean) of (√8 + √2)^2 and (√8 − √2)^2 ?

A. 4
B. 5
C. 8
D. 10
E. 12

_________________
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 4007
Re: What is the average (arithmetic mean) of (√8 + √2)^2 and (√8 − √2)^2 ?  [#permalink]

### Show Tags

17 Oct 2018, 06:42
Top Contributor
Bunuel wrote:
What is the average (arithmetic mean) of (√8 + √2)² and (√8 − √2)² ?

A. 4
B. 5
C. 8
D. 10
E. 12

(√8 + √2)² = (√8 + √2)(√8 + √2)
= 8 + √16 + √16 + 2
= 8 + 4 + 4 + 2
= 18

(√8 - √2)² = (√8 - √2)(√8 - √2)
= 8 - √16 - √16 + 2
= 8 - 4 - 4 + 2
= 2

So, the average = [(√8 + √2)² + (√8 - √2)²]/2
= [18 + 2]/2
= 20/2
= 10

RELATED VIDEO FROM OUR COURSE

_________________
Test confidently with gmatprepnow.com
Re: What is the average (arithmetic mean) of (√8 + √2)^2 and (√8 − √2)^2 ?   [#permalink] 17 Oct 2018, 06:42
Display posts from previous: Sort by