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

It is currently 23 Jun 2018, 07:16

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Given that n = 10^a + 10^b + 10^c, where a, b, and c are distinct

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

Hide Tags

Top Contributor
Senior RC Moderator
User avatar
P
Status: It always seems impossible until it's done!!
Joined: 29 Aug 2012
Posts: 1173
Location: India
WE: General Management (Aerospace and Defense)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Given that n = 10^a + 10^b + 10^c, where a, b, and c are distinct [#permalink]

Show Tags

New post Updated on: 28 Nov 2017, 20:33
Top Contributor
3
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

56% (01:04) correct 44% (01:26) wrong based on 36 sessions

HideShow timer Statistics

Given that \(n = 10^a + 10^b + 10^c\), where a, b, and c are distinct positive integers, how many different positive values of n result if n is less than 1 billion (1,000,000,000) ?

A. 28
B. 36
C. 56
D. 84
E. 120

_________________

Become a GMAT Club Premium member to avail lot of discounts


Originally posted by Gnpth on 28 Nov 2017, 18:47.
Last edited by Bunuel on 28 Nov 2017, 20:33, edited 2 times in total.
Renamed the topic.
Expert Post
3 KUDOS received
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 5936
Given that n = 10^a + 10^b + 10^c, where a, b, and c are distinct [#permalink]

Show Tags

New post 28 Nov 2017, 20:31
3
2
Gnpth wrote:
Given that \(n = 10^a + 10^b + 10^c\), where a, b, and c are distinct positive integers, how many different positive values of n result if n is less than 1 billion (1,000,000,000) ?

A. 28
B. 36
C. 56
D. 84
E. 120



Hi,

The max value of a, b or c can be 8 to Keep the value \(< 10^9\)..
Any of the three a,b, or c being 9 means \(10^9+..+..>10^9\)

Also a,b,c are distinct, so the answer is nothing but choosing 3 out of 8..
here arrangement is not important, so work on COMBINATION
\(8C3=\frac{8!}{5!3!}=\frac{8*7*6}{3*2}=56\)
C
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


GMAT online Tutor

Given that n = 10^a + 10^b + 10^c, where a, b, and c are distinct   [#permalink] 28 Nov 2017, 20:31
Display posts from previous: Sort by

Given that n = 10^a + 10^b + 10^c, where a, b, and c are distinct

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


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.