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

 It is currently 17 Feb 2019, 08:54

### 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
• ### Free GMAT Algebra Webinar

February 17, 2019

February 17, 2019

07:00 AM PST

09:00 AM PST

Attend this Free Algebra Webinar and learn how to master Inequalities and Absolute Value problems on GMAT.
• ### Valentine's day SALE is on! 25% off.

February 18, 2019

February 18, 2019

10:00 PM PST

11:00 PM PST

We don’t care what your relationship status this year - we love you just the way you are. AND we want you to crush the GMAT!

# How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8

Author Message
Manager
Joined: 25 Dec 2018
Posts: 148
Location: India
GMAT 1: 490 Q47 V13
GPA: 2.86
How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8  [#permalink]

### Show Tags

20 Jan 2019, 09:14
1
3
00:00

Difficulty:

45% (medium)

Question Stats:

88% (00:50) correct 13% (02:19) wrong based on 8 sessions

### HideShow timer Statistics

How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8 and 9, without repetition, so that 2 and 5 are not adjacent?

A. 120
B. 180
C. 288
D. 360
E. 720
Director
Joined: 09 Mar 2018
Posts: 958
Location: India
Re: How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8  [#permalink]

### Show Tags

20 Jan 2019, 09:48
2
akurathi12 wrote:
How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8 and 9, without repetition, so that 2 and 5 are not adjacent?

A. 120
B. 180
C. 288
D. 360
E. 720

- - - -

Total 4 digits which can be found without repetition = 6*5*4*3 = 360

Automatically you can remove D and E.

Now in these - - - - dashes, if i consider the cases when 2 & 5 will be adjacent, i can just subtract it from the total
2 5 - -
- 2 5 -
- - 2 5

In each case remaining places will be filled with the remaining 4 numbers in 4 * 3 ways, Total will be 36(since 2 and 5 will take 1 position each)

Order can change as well which will result in 72 ways

4 digit numbers can be formed without repetition, so that 2 and 5 are not adjacent = 360 - 72 = 288

_________________

If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.

Math Expert
Joined: 02 Sep 2009
Posts: 52907
Re: How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8  [#permalink]

### Show Tags

20 Jan 2019, 20:28
akurathi12 wrote:
How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8 and 9, without repetition, so that 2 and 5 are not adjacent?

A. 120
B. 180
C. 288
D. 360
E. 720

Discussed here: https://gmatclub.com/forum/how-many-4-d ... 66550.html
_________________
Re: How many 4 digit numbers can be formed using the digits 1, 2, 5, 6, 8   [#permalink] 20 Jan 2019, 20:28
Display posts from previous: Sort by