Last visit was: 24 Apr 2026, 22:44 It is currently 24 Apr 2026, 22:44
Close
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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
shasadou
Joined: 12 Aug 2015
Last visit: 24 Nov 2022
Posts: 219
Own Kudos:
3,181
 [12]
Given Kudos: 1,475
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)
GMAT 3: 600 Q47 V27
Posts: 219
Kudos: 3,181
 [12]
Kudos
Add Kudos
12
Bookmarks
Bookmark this Post
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 24 Apr 2026
Posts: 11,229
Own Kudos:
45,009
 [2]
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,229
Kudos: 45,009
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
MathRevolution
User avatar
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Last visit: 27 Sep 2022
Posts: 10,063
Own Kudos:
20,001
 [1]
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Expert
Expert reply
GMAT 1: 760 Q51 V42
Posts: 10,063
Kudos: 20,001
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
mangamma
Joined: 25 Dec 2018
Last visit: 12 Jul 2023
Posts: 505
Own Kudos:
1,872
 [1]
Given Kudos: 994
Location: India
Concentration: General Management, Finance
GMAT Date: 02-18-2019
GPA: 3.4
WE:Engineering (Consulting)
Posts: 505
Kudos: 1,872
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Official explanation:

The correct response is (D). We know that average = sum of terms / # of terms. Therefore the sum of all the lizards’ lengths is 80 inches. Statement (1) tells us that none are shorter than 10 inches. If this is true, they must all be 10 inches or more. Since we have 8 lizards total, each of the lizards must be 10 inches. Sufficient. Statement (2) is sufficient for a similar reason. If none of the lizards are longer than 10 inches, then they must all be 10 inches. Sufficient.
User avatar
QuantMadeEasy
Joined: 28 Feb 2014
Last visit: 01 Mar 2026
Posts: 502
Own Kudos:
Given Kudos: 78
Location: India
Concentration: General Management, International Business
GPA: 3.97
WE:Engineering (Education)
Posts: 502
Kudos: 802
Kudos
Add Kudos
Bookmarks
Bookmark this Post
shasadou
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 the average length is 10, there are 2 possibilities; either all lengths are 10, or some lengths more and some lengths less than 10

(1) Lengths are not shorter than 10, which implies all lengths are 10. Sufficient

(2) Lengths are not longer than 10, which implies all lengths are 10. Sufficient

D is correct.
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 24 Apr 2026
Posts: 4,846
Own Kudos:
9,183
 [1]
Given Kudos: 226
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,846
Kudos: 9,183
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
When a question gives you data about the number of values in a data set and the mean of the data set, that’s actually very valuable data. Because, it lets you find the sum of the values in a data set and hence gives you a constraint to work with.

In this question, the number of values in the data set (related to the length of the tegu lizards) is 8 and the average length is 10 inches. Therefore, the sum of the lengths of all the lizards = 8 * 10 = 80 inches.
This means we have 8 values that should add up to 80. Of these 8 values, we are trying to find how many values are equal to 10.

From statement I alone, none of the lizards are shorter than 10 inches. This is only possible by taking all of the values as 10. No other combination of values will satisfy all constraints specified.

For example, if we consider 4 lizards to be 10 inches long, the remaining 4 have to have heights other than 10. If we consider two lizards to be more than 10 inches long, then there will be two lizards which will be less than 10 inches long, which is not possible according to the data given in statement I.

Therefore, we can conclusively say that all the 8 red lizards should be 10 inches long. This is sufficient to answer the question asked.
Statement I alone is sufficient, so, possible answers are A or D. Answer options B, C and E can be eliminated.

From statement II alone, none of the lizards are longer than 10 inches. Again, in a similar way, we can say that this is satisfied only when all the lizards are of the same length and that is 10 inches.
Statement II alone is sufficient. Answer option A can be eliminated.

The correct answer option is D.

If you observe carefully, the individual statements are giving you information about the minimum and maximum values of the lengths of the lizards. When you couple this information with a constraint like the one given in the question (i.e. the sum should be 80), it’s easy pickings. The only combination that will fit will be the one with all values equal. This is a commonly tested concept (equalizing values to maximise or minimize) on the GMAT.

Hope that helps!
User avatar
sanya2711
Joined: 19 Jan 2021
Last visit: 11 Aug 2024
Posts: 79
Own Kudos:
Given Kudos: 225
Location: India
GMAT 1: 690 Q49 V34
GPA: 3.57
GMAT 1: 690 Q49 V34
Posts: 79
Kudos: 15
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel Can you pls solve this doubt for me. for the second statement, I thought that since the total sum should be 80 it would e perfectly fine to have 7 lizards of 8 cm each and 1 of 24 cm. The average remains the same and thus i chose option A. Can you pls tell me why this is wrong?
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 24 Apr 2026
Posts: 109,818
Own Kudos:
811,094
 [1]
Given Kudos: 105,873
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 109,818
Kudos: 811,094
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sanya2711
Bunuel Can you pls solve this doubt for me. for the second statement, I thought that since the total sum should be 80 it would e perfectly fine to have 7 lizards of 8 cm each and 1 of 24 cm. The average remains the same and thus i chose option A. Can you pls tell me why this is wrong?

(2) says "None of the red tegu lizards are longer than 10 inches", so a lizard cannot be 24 inches long.
User avatar
sanya2711
Joined: 19 Jan 2021
Last visit: 11 Aug 2024
Posts: 79
Own Kudos:
Given Kudos: 225
Location: India
GMAT 1: 690 Q49 V34
GPA: 3.57
GMAT 1: 690 Q49 V34
Posts: 79
Kudos: 15
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel
sanya2711
Bunuel Can you pls solve this doubt for me. for the second statement, I thought that since the total sum should be 80 it would e perfectly fine to have 7 lizards of 8 cm each and 1 of 24 cm. The average remains the same and thus i chose option A. Can you pls tell me why this is wrong?

(2) says "None of the red tegu lizards are longer than 10 inches", so a lizard cannot be 24 inches long.
Thanks Bunuel !!! Totally missed that.
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,978
Own Kudos:
Posts: 38,978
Kudos: 1,117
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Math Expert
109818 posts
498 posts
212 posts