m1 questions : Retired Discussions [Locked]
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 22 Jan 2017, 14:09

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# m1 questions

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Manager
Joined: 04 Jan 2009
Posts: 241
Followers: 1

Kudos [?]: 12 [0], given: 0

m1 questions [#permalink]

### Show Tags

08 Nov 2009, 16:18
How many times does 7 appear in all the numbers between 1 to 1000?

I am not arriving at the answer.
Here is how I did it:
between 0 and 100, 7 appears in the following 7, 17, 27, 37, 47, 57, 67, 87, 97 (9 times+ 10 times from 70 to 79)
So a total of 19 times.
For each 100, this pattern repeats. So, I get 19*10 for everywhere between 0 and 1000
For 700 to 700, we get 100 more. So, I get 290.

What did I miss?
Manager
Joined: 01 Jan 2009
Posts: 96
Location: India
Schools: LBS
Followers: 2

Kudos [?]: 79 [0], given: 6

Re: m1 questions [#permalink]

### Show Tags

08 Nov 2009, 20:51
tusharvk wrote:
How many times does 7 appear in all the numbers between 1 to 1000?

I am not arriving at the answer.
Here is how I did it:
between 0 and 100, 7 appears in the following 7, 17, 27, 37, 47, 57, 67, 87, 97 (9 times+ 10 times from 70 to 79)
So a total of 19 times.
For each 100, this pattern repeats. So, I get 19*10 for everywhere between 0 and 1000
For 700 to 700, we get 100 more. So, I get 290.

What did I miss?

since 7s from 700 to 799 are being added , u need to ignore the 7s in 700s when multplying with 19.

so 19*9 + 100 = 271

and i think the question wants how many times 7 appears. Not how many numbers with 7 are there.

so 77 would add 2, 777 would add 3 etc.

so that makes 20 7s in a hundred.
so 20x9 = 180

now from 700-799.

u got 100(7 in the hundreds) + 10(7 in the tens) +10 (7 in the ones) = 120

so total = 180+120 = 300
_________________

The Legion dies, it does not surrender.

Re: m1 questions   [#permalink] 08 Nov 2009, 20:51
Similar topics Replies Last post
Similar
Topics:
m1-#18 3 18 Jul 2011, 14:17
Probability Question 3 06 Sep 2010, 17:50
M1 q19 error? 1 15 Nov 2009, 09:30
Hardest Questions 1 12 Aug 2009, 14:16
GMAT Question 3 07 Jun 2009, 13:25
Display posts from previous: Sort by

# m1 questions

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

Moderator: Bunuel

 Powered by phpBB © phpBB Group and phpBB SEO 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®.