It is currently 17 Oct 2017, 01:04

### 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 June
Open Detailed Calendar

# If the units digit of integer n is greater than 2, what is

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 41872

Kudos [?]: 128493 [0], given: 12179

If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 03:00
Expert's post
13
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

77% (01:04) correct 23% (00:58) wrong based on 1047 sessions

### HideShow timer Statistics

If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2.
(2) The units digit of n is the same as the units digit of n^3.

Diagnostic Test
Question: 25
Page: 25
Difficulty: 600
[Reveal] Spoiler: OA

_________________

Kudos [?]: 128493 [0], given: 12179

Math Expert
Joined: 02 Sep 2009
Posts: 41872

Kudos [?]: 128493 [1], given: 12179

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 03:00
1
KUDOS
Expert's post
1
This post was
BOOKMARKED
SOLUTION

If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2 --> since the units digit of n is greater than 2, then its units digit could be 5 or 6 (if we were not told that the units digit of n is greater than 2, then it cold also be 0 and 1). For example, both 45 and 45^2 have the units digit of 5, similarly both 26 and 26^2 have the units digit of 6. Not sufficient.

(2) The units digit of n is the same as the units digit of n^3 --> the units digit of n could be 4, 5, 6, or 9. Not sufficient.

(1)+(2) The units digit of n could still be 5 or 6. Not sufficient.

Difficulty level changed to 600.
_________________

Kudos [?]: 128493 [1], given: 12179

Manager
Joined: 25 Jun 2012
Posts: 56

Kudos [?]: 23 [1], given: 2

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 07:24
1
KUDOS
Hi there,

I'd approach this question by essentially "brute-forcing" it with a couple of quick number substitutions. The multiplication table for each integer should come very easily to anyone taking the GMAT. This allows us to run through the entire set of integers very quickly, and should not take more than a minute or so.

xxx5^2 = yyy5, xxx5^3 = yyy5

Similarly, integers ending with 6, when squared or cubed, result in integers still ending in 6.

Neither of these statements is sufficient, either alone or in combination with the other.

With regard to the question difficulty - 650 seems like it might be about right, although a lower score could work, too. As noted above, brute-forcing it works well enough and is not even particularly time-consuming. This is, I feel, an indication that the question is not very difficult.

- MrFong

Kudos [?]: 23 [1], given: 2

Math Expert
Joined: 02 Sep 2009
Posts: 41872

Kudos [?]: 128493 [0], given: 12179

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 07:32
MrFong wrote:
Hi there,

I'd approach this question by essentially "brute-forcing" it with a couple of quick number substitutions. The multiplication table for each integer should come very easily to anyone taking the GMAT. This allows us to run through the entire set of integers very quickly, and should not take more than a minute or so.

xxx5^2 = yyy5, xxx5^3 = yyy5

Similarly, integers ending with 6, when squared or cubed, result in integers still ending in 6.

Neither of these statements is sufficient, either alone or in combination with the other.

With regard to the question difficulty - 650 seems like it might be about right, although a lower score could work, too. As noted above, brute-forcing it works well enough and is not even particularly time-consuming. This is, I feel, an indication that the question is not very difficult.

- MrFong

Thank you. I also thought that it was not a hard problem. Though I'll wait for other comments and then might change difficulty to 600.
_________________

Kudos [?]: 128493 [0], given: 12179

Senior Manager
Joined: 06 Aug 2011
Posts: 390

Kudos [?]: 233 [0], given: 82

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 12:17
Bunuel wrote:
The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2.
(2) The units digit of n is the same as the units digit of n^3.

Diagnostic Test
Question: 25
Page: 25
Difficulty: 650

GMAT Club is introducing a new project: The Official Guide for GMAT® Review, 13th Edition - Quantitative Questions Project

Each week we'll be posting several questions from The Official Guide for GMAT® Review, 13th Edition and then after couple of days we'll provide Official Explanations (OE) to them along with an alternate approaches if necessary.

We'll be glad if you participate in development of this project:
2. Please vote for the best solutions by pressing Kudos button (the best solution we'll be put along the OE in the second post);
3. Please vote for the questions themselves by pressing Kudos button;
4. Please share your views on difficulty level of the questions, so that we have most precise evaluation.

Thank you!

Its E bunuel??

Take 6 .. its square unit digit is 6..and cube unit digit is 6..
Take 5 ..again its square and cube unit digit is 5..

So i think E is the answer..
_________________

Bole So Nehal.. Sat Siri Akal.. Waheguru ji help me to get 700+ score !

Kudos [?]: 233 [0], given: 82

Joined: 29 Mar 2012
Posts: 322

Kudos [?]: 511 [2], given: 23

Location: India
GMAT 1: 640 Q50 V26
GMAT 2: 660 Q50 V28
GMAT 3: 730 Q50 V38
Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

14 Jun 2012, 23:09
2
KUDOS
Hi,

Difficulty level: 600

Since, unit digit is greater than 2,
then, possible digits at unit place would be:
3: Unit digit of $$3^2=9, 3^3=7$$
4: Unit digit of $$4^2=6, 4^3=4$$
5: Unit digit of $$5^2=5, 5^3=5$$
6: Unit digit of $$6^2=6, 6^3=6$$
7: Unit digit of $$7^2=9, 7^3=3$$
8: Unit digit of $$8^2=4, 8^3=2$$
9: Unit digit of $$9^2=1, 9^3=9$$

Using (1),
Unit digit can be:
5: Unit digit of $$5^2=5$$
6: Unit digit of $$6^2=6$$. Insufficient.

Using (2),
Unit digit can be:
4: Unit digit of $$4^3=4$$
5: Unit digit of $$5^3=5$$
6: Unit digit of $$6^3=6$$. Insufficient.

Combining both the statements:
Unit digit can either be 5 or 6. Insufficient.

Regards,

Kudos [?]: 511 [2], given: 23

Manager
Joined: 07 Sep 2011
Posts: 63

Kudos [?]: 40 [0], given: 3

Location: United States
GMAT 1: 640 Q39 V38
WE: General Management (Real Estate)
Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

16 Jun 2012, 04:18
Difficulty level: 600+

I simply noted down numbers from 3 to 9 and checked square and cube values. Found 5 and 6 given similar answers.

E for me

Kudos [?]: 40 [0], given: 3

Math Expert
Joined: 02 Sep 2009
Posts: 41872

Kudos [?]: 128493 [0], given: 12179

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

22 Jun 2012, 03:14
SOLUTION

If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2 --> since the units digit of n is greater than 2, then its units digit could be 5 or 6 (if we were not told that the units digit of n is greater than 2, then it cold also be 0 and 1). For example, both 45 and 45^2 have the units digit of 5, similarly both 26 and 26^2 have the units digit of 6. Not sufficient.

(2) The units digit of n is the same as the units digit of n^3 --> the units digit of n could be 4, 5, 6, or 9. Not sufficient.

(1)+(2) The units digit of n could still be 5 or 6. Not sufficient.

Difficulty level changed to 600.
_________________

Kudos [?]: 128493 [0], given: 12179

Director
Status: Final Countdown
Joined: 17 Mar 2010
Posts: 536

Kudos [?]: 353 [0], given: 75

Location: India
GPA: 3.82
WE: Account Management (Retail Banking)
Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

23 Jul 2012, 07:36
If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2.
n=5,6 both greater than 2
5^2=25
6^2=36
not sufficient
(2) The units digit of n is the same as the units digit of n^3.
n=4,5,6,9
4^3=64
5^3=125
6^3=216
9^3=729
not sufficient
from (i) and (ii)
5 & 6 not sufficient
(E)
_________________

" Make more efforts "
Press Kudos if you liked my post

Kudos [?]: 353 [0], given: 75

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16767

Kudos [?]: 273 [0], given: 0

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

19 Oct 2014, 21:16
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.
_________________

Kudos [?]: 273 [0], given: 0

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16767

Kudos [?]: 273 [0], given: 0

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

15 Dec 2015, 16:38
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.
_________________

Kudos [?]: 273 [0], given: 0

BSchool Forum Moderator
Joined: 12 Aug 2015
Posts: 2213

Kudos [?]: 836 [0], given: 595

Re: If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

03 Dec 2016, 22:19
Here is my solution ->
Units digit of n>2
so the unit digit of n can be => {3,4,...9}
we need the unit digit of n
Lets dive into statements
Statement 1
Unit digit of n = units digit of n^2
so the units digits of n can be 5 or 6
Not sufficient
Statement 2
Units digit of n =units digit of n^3
so the units digit of n^3 can be {4,5,6,9}
Hence not sufficient
Statement 1 and statement 2
units digit of n can be 5 or 6
Hence insufficient
Hence E

_________________

Give me a hell yeah ...!!!!!

Kudos [?]: 836 [0], given: 595

Manager
Joined: 13 Aug 2015
Posts: 204

Kudos [?]: 67 [0], given: 64

GMAT 1: 710 Q49 V38
GPA: 3.82
WE: Corporate Finance (Retail Banking)
If the units digit of integer n is greater than 2, what is [#permalink]

### Show Tags

12 Jul 2017, 07:39
Bunuel wrote:
If the units digit of integer n is greater than 2, what is the units digit of n ?

(1) The units digit of n is the same as the units digit of n^2.
(2) The units digit of n is the same as the units digit of n^3.

Diagnostic Test
Question: 25
Page: 25
Difficulty: 600

Theory:
unit-digit^p = unit-digit, when unit-digit is 0,1,5,6. p may be odd or even

(--4)^odd=4
(--9)^odd=9

Statement 1.
5,6 (not, 4 and 9 because the power is square(even)). Insufficient

statement 2.
5,6, and 4,9. Insufficient

Statement 1 and 2.
5,6. Two values so insufficient

Hence, Ans is E
_________________

If you like my posts, please give kudos. Help me unlock gmatclub tests.

Kudos [?]: 67 [0], given: 64

If the units digit of integer n is greater than 2, what is   [#permalink] 12 Jul 2017, 07:39
Display posts from previous: Sort by