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

 It is currently 18 Sep 2018, 10:40

### 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
Your Progress

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

# There are 8 red tegu lizards in the reptile house at a local zoo. If

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Current Student
Joined: 12 Aug 2015
Posts: 287
Concentration: General Management, Operations
GMAT 1: 640 Q40 V37
GMAT 2: 650 Q43 V36
GMAT 3: 600 Q47 V27
GPA: 3.3
WE: Management Consulting (Consulting)
There are 8 red tegu lizards in the reptile house at a local zoo. If t  [#permalink]

### Show Tags

23 Jan 2016, 08:15
5
00:00

Difficulty:

35% (medium)

Question Stats:

70% (00:19) correct 30% (00:18) wrong based on 94 sessions

### HideShow timer Statistics

There are 8 red tegu lizards in the reptile house at a local zoo. If the average length of the red tegu lizards is 10 inches, then how many of the red tegu lizards are exactly 10 inches long?

(1) None of the red tegu lizards are shorter than 10 inches.

(2) None of the red tegu lizards are longer than 10 inches.

_________________

KUDO me plenty

Math Expert
Joined: 02 Aug 2009
Posts: 6785
Re: There are 8 red tegu lizards in the reptile house at a local zoo. If t  [#permalink]

### Show Tags

23 Jan 2016, 09:07
1
1
shasadou wrote:
There are 8 red tegu lizards in the reptile house at a local zoo. If the average length of the red tegu lizards is 10 inches, then how many of the red tegu lizards are exactly 10 inches long?

(1) None of the red tegu lizards are shorter than 10 inches.

(2) None of the red tegu lizards are longer than 10 inches.

Hi,
It is given that the average length is 10 inches..

lets see the choices..

(1) None of the red tegu lizards are shorter than 10 inches.
since none are shorter than 10 inches, none can be greater than 10 inches.. otherwise the average will become > 10..
all are 10 inches.. suff

(2) None of the red tegu lizards are longer than 10 inches.
SAME as (1)...suff

D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6204
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: There are 8 red tegu lizards in the reptile house at a local zoo. If t  [#permalink]

### Show Tags

23 Jan 2016, 23:52
1
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

There are 8 red tegu lizards in the reptile house at a local zoo. If the average length of the red tegu lizards is 10 inches, then how many of the red tegu lizards are exactly 10 inches long?

(1) None of the red tegu lizards are shorter than 10 inches.

(2) None of the red tegu lizards are longer than 10 inches.

When you modify the original condition and the question, there are avg=10, 8 variables, 1 equation(avg=10), which should match with the number of equations. So you need 7 equations. For 1) 1 equation, for 2) 1 equation, which is likely to make E the answer.

When 1) & 2), in 1), none shorter than= at least=min=avg -> standard deviation=0 -> the length of all 8 lizards is 10, which is sufficient.
In 2), none longer than= at most=MaAx=avg -> standard deviation=0 -> the length of all 8 lizards is 10, which is sufficient, which is sufficient. Therefore the answer is D. This type of question is a current trend found in GMAT Math.

-> For cases where we need 3 more equations, such as original conditions with “3 variables”, or“4 variables and 1 equation”, or “5 variables and 2 equations”, we have 1 equation each in both 1) and 2). Therefore, there is 80% chance that E is the answer (especially about 90% of 2 by 2 questions where there are more than 3 variables), while C has 15% chance. These two are the majority. In case of common mistake type 3,4, the answer may be from A, B or D but there is only 5% chance. Since E is most likely to be the answer using 1) and 2) separately according to DS definition (It saves us time). Obviously there may be cases where the answer is A, B, C or D.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Non-Human User
Joined: 09 Sep 2013
Posts: 8065
Re: There are 8 red tegu lizards in the reptile house at a local zoo. If  [#permalink]

### Show Tags

03 Oct 2017, 02:56
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: There are 8 red tegu lizards in the reptile house at a local zoo. If &nbs [#permalink] 03 Oct 2017, 02:56
Display posts from previous: Sort by

# There are 8 red tegu lizards in the reptile house at a local zoo. If

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

# 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®.