Tricky question : GMAT Quantitative Section
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 24 Jan 2017, 04:10

### 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

# Tricky question

Author Message
TAGS:

### Hide Tags

Intern
Joined: 25 Apr 2012
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 6

### Show Tags

19 Jun 2012, 21:20
Hi,
I have got two questions that I would like to understand the difference in solutions.

1) How many even, three digit integers greater than 700 with distinct, non- zero digits are there
2) How many odd three-digit integers greater than 800 are there such that all their digits are different?

Thx
Intern
Joined: 07 Nov 2011
Posts: 40
Location: India
Concentration: Marketing, Other
GMAT Date: 10-26-2012
GPA: 2.5
WE: Operations (Consulting)
Followers: 0

Kudos [?]: 5 [0], given: 8

### Show Tags

19 Jun 2012, 21:41
If the first digit is 7 then u cant use the no in tens place .. so u will be having 8 other different nos .. and in last place u will be having 7. So in total 1*8*7 = 56
This is for the numbers starting with 7 . Similar goes for nos starting with 8 & 9 .. So the total nos available will be equal to 56 *3 = 168
Joined: 28 Mar 2012
Posts: 314
Location: India
GMAT 1: 640 Q50 V26
GMAT 2: 660 Q50 V28
GMAT 3: 730 Q50 V38
Followers: 29

Kudos [?]: 399 [0], given: 23

### Show Tags

19 Jun 2012, 23:11
Hi,

1) You have to find the even (3 digit) numbers greater than 700, with non-zero digits as well as distict digits. So, available digits would be (1 to 9)
Even numbers starting with 7 = 1*7*4 = 28 (Hundredth digit is 7 - so, only 1 choice, unit digit can be (2, 4, 6, 8). Now tens digit will not be 7 & a digit chosen at units place - 7 possibilities)
Even numbers starting with 8 = 1*7*3 = 21
Even numbers starting with 9 = 1*7*4 = 28
Total numbers = 77

2) You have to find the odd (3digit) numbers greater than 800, all distict digits. Available digits would be (0 to 9)
Odd numbers starting with 8 = 1*8*5 = 40 (Hundredth digit is 8 - so, only 1 choice. Unit digit can be (1, 3, 5, 7, 9). Now tens digit will not be 8 & a digit chosen at units place - 8 possibilities)
Odd numbers starting with 9 = 1*8*4 = 40 (Hundredth digit is 9 - so, only 1 choice. Unit digit can be (1, 3, 5, 7). Now tens digit will not be 9 & a digit chosen at units place - 8 possibilities)
Total numbers = 32

Let me know, if you need any further help on this.

Regards,
Math Expert
Joined: 02 Sep 2009
Posts: 36625
Followers: 7104

Kudos [?]: 93625 [1] , given: 10583

### Show Tags

20 Jun 2012, 00:20
1
KUDOS
Expert's post
Suren2012 wrote:
Hi,
I have got two questions that I would like to understand the difference in solutions.

1) How many even, three digit integers greater than 700 with distinct, non- zero digits are there
2) How many odd three-digit integers greater than 800 are there such that all their digits are different?

Thx

The first question is discussed here: how-many-even-3-digit-integers-greater-than-700-with-9358.html
The second question is discussed here: how-many-odd-three-digit-integers-greater-than-800-are-there-94655.html

Topic is locked.
_________________
Re: Tricky question   [#permalink] 20 Jun 2012, 00:20
Similar topics Replies Last post
Similar
Topics:
2 Tricky Absolute Value Question 3 06 Feb 2013, 04:20
Tricky question 2 23 Nov 2011, 05:28
Tricky Math Question - Error in Question (pls do not refer) 5 13 Feb 2011, 00:48
help required on this tricky question 1 29 Nov 2010, 14:03
361 50 tricky questions 78 17 Apr 2010, 08:02
Display posts from previous: Sort by