Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 20 May 2013, 06:44
Customize  |  Hide

Search
Register
New posts
Unanswered

If each term in the sum A1 + A2 + .....+ An is either 7 or

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Director
Director
User avatar
Joined: 08 Jun 2007
Posts: 586
Followers: 1

Kudos [?]: 66 [0], given: 0

GMAT Tests User
If each term in the sum A1 + A2 + .....+ An is either 7 or [#permalink] New post 15 Dec 2007, 20:26
00:00

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If each term in the sum A1 + A2 + .....+ An is either 7 or 77 and the sum equals 350
,which of the following could be equal to n ?

A 38
B 39
C 40
D 41
E 42
CEO
CEO
User avatar
Joined: 29 Mar 2007
Posts: 2618
Followers: 13

Kudos [?]: 142 [0], given: 0

GMAT Tests User
Re: PS - GmatPrep [#permalink] New post 15 Dec 2007, 21:58
ashkrs wrote:
If each term in the sum A1 + A2 + .....+ An is either 7 or 77 and the sum equals 350
,which of the following could be equal to n ?

A 38
B 39
C 40
D 41
E 42


I get C.

Took me about 1min 30 sec, but it seems to work...

Just tried values 7*38=266 +77=343 +7

So 39*7 +77=350.

Unless Im missin somethin.
Director
Director
User avatar
Joined: 08 Jun 2007
Posts: 586
Followers: 1

Kudos [?]: 66 [0], given: 0

GMAT Tests User
Re: PS - GmatPrep [#permalink] New post 15 Dec 2007, 22:06
GMATBLACKBELT wrote:
ashkrs wrote:
If each term in the sum A1 + A2 + .....+ An is either 7 or 77 and the sum equals 350
,which of the following could be equal to n ?

A 38
B 39
C 40
D 41
E 42


I get C.

Took me about 1min 30 sec, but it seems to work...

Just tried values 7*38=266 +77=343 +7

So 39*7 +77=350.

Unless Im missin somethin.


no u are not missin anythin....OA is C.
but how did you arrived..on 7*38=266 +77=343 +7

i tried plugging too ..but tool hell lotta time for me to put all combinations ..before i arrived at c ..just wanted to know whats the best way to do this..
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3594
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 230

Kudos [?]: 1298 [0], given: 346

GMAT ToolKit User GMAT Tests User
 [#permalink] New post 16 Dec 2007, 02:32
C.

other way.

350/7=50 but 50 is out of answer cases.

we add one 77 and exclude eleven 7, so 350=(50-11)*7+1*77 ==> n=50-11+1=40
Manager
Manager
Joined: 12 Jun 2006
Posts: 55
Followers: 1

Kudos [?]: 1 [0], given: 0

 [#permalink] New post 17 Dec 2007, 00:26
walker wrote:
C.

other way.

350/7=50 but 50 is out of answer cases.

we add one 77 and exclude eleven 7, so 350=(50-11)*7+1*77 ==> n=50-11+1=40
Sorry I didn't understand how you came up with the above equation? Plz elaborate
CEO
CEO
User avatar
Joined: 17 Nov 2007
Posts: 3594
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 230

Kudos [?]: 1298 [0], given: 346

GMAT ToolKit User GMAT Tests User
 [#permalink] New post 17 Dec 2007, 00:40
lonesome307 wrote:
Sorry I didn't understand how you came up with the above equation? Plz elaborate


step 1. we can represent 350 as a sum of only 7. 350=50*7. So, we should sum 50 terms - out of answers.

step 2. we add one 77 and exclude eleven 7 to balance the sum: 350=50*7+1*77-11*7=50*39+1*77. we have 40 terms.

we had gone to the next step if 40 would not be answer.

possible step: add next 77 and exclude eleven 7 to balance question:
350=50*7+2*77-22*7=50*28+2*77. we have 30 terms.
1 KUDOS received
Manager
Manager
Joined: 03 Sep 2006
Posts: 237
Followers: 1

Kudos [?]: 5 [1] , given: 0

GMAT Tests User
 [#permalink] New post 17 Dec 2007, 01:35
1
This post received
KUDOS
Late, but C:

350 = 7*50 (but we don't have such answer)
350-77 = 273 (and 273/7 = 39), so answer is 40.

walker, nice trick - noted!
  [#permalink] 17 Dec 2007, 01:35
    Similar topics Author Replies Last post
Similar
Topics:
 New posts If each term in the sum A1+A2+...+ An is either 7 or 77 and sm176811 7 16 Apr 2006, 04:14
New posts If each term in the sum a1 + a2,..., + aN is either 7 or 77 raconteur 5 13 Apr 2007, 20:37
New posts If each term in sum a1+a2+....+an is either 7 or 77 and sum r019h 2 30 Oct 2007, 20:22
Popular new posts 2 If each term in the sum a1 + a2 + ... + an is either 7 or 77 tarek99 11 29 Sep 2008, 09:45
New posts 2 If each term in the sum A1+A2+ An is either 7 or 77 and the shobuj40 3 01 Jan 2009, 12:49
Display posts from previous: Sort by

If each term in the sum A1 + A2 + .....+ An is either 7 or

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma, IanStewart

Search for:


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

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com