|
Author |
Message |
|
TAGS:
|
|
|
GMAT Instructor
Joined: 04 Jul 2006
Posts: 1278
Location: Madrid
Followers: 9
Kudos [?]:
69
[0], given: 0
|
How many positive three-digit positive integers are [#permalink]
 19 Sep 2006, 13:43
Question Stats:
0% (00:00) correct
 0% (00:00) wrong based on 1 sessions
How many positive three-digit positive integers are multiples of 6, 9 and 7?
(A) 3 (B) 4 (C) 6 (D) 7 (E) 8
Last edited by kevincan on 19 Sep 2006, 14:11, edited 1 time in total.
|
|
|
|
|
|
|
VP
Joined: 02 Jun 2006
Posts: 1278
Followers: 2
Kudos [?]:
15
[0], given: 0
|
(D) 7
I am presuming multiples of 6 & 7 & 9, not independently.
LCM (6,7,9) = 126
Three digit +ve integers... {100... 999}
First multiple of 126 after 100 = 126
Last multiple of 126 < 999 = 882
# of multiples = (882-126)/126 +1 (inclusive)
= 7-1 +1 = 7
Answer: D. 7
|
|
|
|
|
|
SVP
Joined: 05 Jul 2006
Posts: 1565
Followers: 4
Kudos [?]:
63
[0], given: 34
|
How many positive three-digit positive integers are multiples of 6, 9 and 7?
(A) 3 (B) 4 (C) 6 (D) 7 (E) 8
the intiger will be in the form of LCM OF (6,9,7)*K WHERE K IS ANY POSITIVE INTIGER
lcm = 7*3^2*2 = 126
now lets name our intiger K
126 < 126K<999
1< K <7.9...K COULD ONLY BE INTIGER , THUS 1=<K=<7
NUMBER OF MULTIPLES IS THUS 7-1+1 = 7
|
|
|
|
|
|
SVP
Joined: 05 Jul 2006
Posts: 1565
Followers: 4
Kudos [?]:
63
[0], given: 34
|
Kevin .. would u plz send OA...THANKS IN ADVANCE
|
|
|
|
|
|
Manager
Joined: 14 Sep 2006
Posts: 198
Schools: Olin Business School - Washington University
Followers: 1
Kudos [?]:
1
[0], given: 0
|
Got 7 too, but muscled thru it, not the most efficient way. I like your explanation Yezz...
|
|
|
|
|
|
SVP
Joined: 05 Jul 2006
Posts: 1565
Followers: 4
Kudos [?]:
63
[0], given: 34
|
Die Gmat....thanks man..........i had no clue about this way before joining our forum here so thanks to Gmat club and each and every member in it.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
close
