OG - DS - #146

[cindyqtran]

Page 336 from the 11th edition OFFICIAL GUIDE Question 146

can you please explain why n^2 is an integer is NOT sufficient? if N^2 is an integer, it means that N is NOT a fraction, therefore an integer, correct?

Thanks.

[StaceyKoprince]

Please don't forget to post the entire text of the question and answer choices. Others would like to study from the questions you ask, and that is made much more difficult if they cannot see the whole question. Unfortunately, there are too many requests every day for the instructors to look up and transcribe all of the questions.

Thanks!

[sharad]

Have trouble understanding the solution to the same question... so here's the problem:

#146
Is n an integer?
1) n^2 is an int
2) sqrt n is an int

OG Ans: B

Why isn't it D?

[sharad]

Found this post - that explains why... makes sense... thanks,

DS question

is n an integer?
1) n^2 is an integer

in the statement above, can anyone provide me with an example of n not being an integer when n^2 is an integer? thanks.

If n = 1.414.....(the square root of 2), then n is not an integer when n^2 is. As Saurabh mentioned, this works with any non-perfect square situation, such as root3, root5, root6, root7, etc. Notice that with a perfect square, such as the number 4, this does not hold true.

Hope this helps!