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

Redeem

properties of numbes - is n an integer?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Sun Oct 19, 2008 8:45 pm

properties of numbes - is n an integer?

by heffsz » Tue Dec 02, 2008 8:53 am
Can anyone explain the below? I've read the OG explanation (#146) but still don't understand how (1) is false but (2) is true. I thought the answer was D and not B. Could anyone give me an example where a non integer thats squared results in an integer?

Is n an integer?
(1) n^2 is an integer
(2) Square root of n is an integer.

Thanks!
Top
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 64
Joined: Sat Oct 18, 2008 10:32 am
Location: Phoenix
Thanked: 1 times

by gkammaje » Tue Dec 02, 2008 9:25 am
two most simple examples are-
(1.4)^2 = 2
(1.7)^2 = 3

hope this helps
Top
Master | Next Rank: 500 Posts
Posts: 110
Joined: Thu Oct 23, 2008 9:12 am
Location: India
Thanked: 9 times
Followed by:1 members

by austin » Tue Dec 02, 2008 9:49 am
n^2 is an integer
n^2 = 64 -> n = 8, an integer
n^2 = 63 -> n - 7.9, not an integer
INCONSISTENT ANSWERS

Square root of n is an integer.
n^1/2 = 64 -> n = 64*64, an integer
n^1/2 = 63 -> n = 63*63, an integer
ALWAYS TRUE B
Top
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Sun Oct 19, 2008 8:45 pm

by heffsz » Tue Dec 02, 2008 6:08 pm
thanks for the responses gkammaje and austin. i originally thought about 1.4 and 1.7 but when you square either of these numbers it doesnt come out to be exactly 2 or 3. same goes for 7.9 and 63. isn't this a bit of a problem?

again, thanks for the help.
Top
Post new topic Post Reply
• Page 1 of 1