BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

the three digit pos

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 85
Joined: Mon Dec 08, 2008 12:09 am

the three digit pos

by tj123 » Wed Aug 05, 2009 10:18 pm
The three digit positive integer N = a2b is both a multiple of 3 and a multiple of 5. what is N?

1)a+b is an even integer

2)a/b = 1


will post OA after some discussion
Top
Source: — Data Sufficiency |
Legendary Member
Posts: 752
Joined: Sun May 17, 2009 11:04 pm
Location: Tokyo
Thanked: 81 times
GMAT Score:680

by tohellandback » Wed Aug 05, 2009 10:34 pm
IMO B

N = a2b, where N is a multiple of 3 and a multiple of 5
so b must be 5 or 0


1)a+b is an even integer
when b=5, a=5
when b=0, a =4
not sufficient

2)a/b=1
in this case b not equal to 0. so b must be 5 and hence a must be 5
N is 525
sufficient
The powers of two are bloody impolite!!
Top
Junior | Next Rank: 30 Posts
Posts: 10
Joined: Sun Aug 02, 2009 11:51 am
GMAT Score:710

by ram_raj » Thu Aug 06, 2009 3:22 am
IMO B.

Agree with the above explanation .
Top
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Jul 13, 2009 7:40 pm

by baha777 » Thu Aug 06, 2009 9:15 am
Definitely "B".
Since "5" has less multiples available in 3 digit integer, lets choose "5" to test. 5 has multiple integers that end with either 0 or 5. With the statement 2 showing first and third digit in the 3-digit integer being the same, once you test (121, 222, 323, 424, 525, 626, 727, 828 and 929), only 525 has both factors of 3 and 5.
Top
Senior | Next Rank: 100 Posts
Posts: 85
Joined: Mon Dec 08, 2008 12:09 am

by tj123 » Thu Aug 06, 2009 8:25 pm
OA is B
Top
Post new topic Post Reply
• Page 1 of 1