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

It is currently 18 Jul 2018, 02:06

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

How many times will the digit 7 be written?

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

Hide Tags

BSchool Forum Moderator
User avatar
D
Joined: 28 Mar 2017
Posts: 1041
Location: India
Concentration: Finance, Technology
GMAT 1: 730 Q49 V41
GPA: 4
CAT Tests
Re: How many times will the digit 7 be written? [#permalink]

Show Tags

New post 10 Mar 2018, 06:24
seekmba wrote:
How many times will the digit 7 be written when listing the integers from 1 to 1000?

(A) 110
(B) 111
(C) 271
(D) 300
(E) 304


_ _ _

1. When all are 7, we have 1 combination i.e. 7 7 7 and since 7 appears 3 times we have 1*3= 3

2. When we have 2 7s, 7 7 _, we can fill the dash with 9 remaining digits and these can be further arranged in 3 ways.
Total ways = 9*3=27; but 7 appears 2 times in each combination; thus we have 27*2 = 54

3. When we have 1 7; 7 _ _ , we can fill the remaining dashes with remainng 9 digits.
Total ways = 9*9*3= 243

Thus Final Total = 243+54+3 = 300
_________________

Kudos if my post helps!

Long And A Fruitful Journey - V21 to V41; If I can, So Can You!!


Preparing for RC my way


My study resources:
1. Useful Formulae, Concepts and Tricks-Quant
2. e-GMAT's ALL SC Compilation
3. LSAT RC compilation
4. Actual LSAT CR collection by Broal
5. QOTD RC (Carcass)
6. Challange OG RC
7. GMAT Prep Challenge RC

Re: How many times will the digit 7 be written?   [#permalink] 10 Mar 2018, 06:24

Go to page   Previous    1   2   3   [ 42 posts ] 

Display posts from previous: Sort by

How many times will the digit 7 be written?

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

Events & Promotions

PREV
NEXT


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®.