Question on Perfect Square 3

Expert replies

richachampion: Legendary Member; Posts: 698; Joined: Tue Jul 21, 2015 12:12 amFollowed by: 26 members; Location: Noida, India; Thanked: 32 times; GMAT Score:740

by richachampion » Sun Oct 16, 2016 3:05 am

Is the positive integer x a perfect square?

(1) x = t^n, where t is a positive integer and n is odd.
(2) x^0.5=k, where k is a positive integer.

R I C H A,
My GMAT Journey: 470 â†’ 720 â†’ 740
Target Score: 760+
[email protected]
1. Press thanks if you like my solution.
2. Contact me if you are not improving. (No Free Lunch!)

Like this post

Source: Beat The GMAT — Data Sufficiency | Sun Oct 16, 2016 3:05 am

richachampion: Legendary Member; Posts: 698; Joined: Tue Jul 21, 2015 12:12 amFollowed by: 26 members; Location: Noida, India; Thanked: 32 times; GMAT Score:740

by richachampion » Sun Oct 16, 2016 3:06 am

OA: B

R I C H A,
My GMAT Journey: 470 â†’ 720 â†’ 740
Target Score: 760+
[email protected]
1. Press thanks if you like my solution.
2. Contact me if you are not improving. (No Free Lunch!)

Like this post

fiza gupta: Master | Next Rank: 500 Posts; Posts: 216; Joined: Sun Jul 31, 2016 9:55 pmFollowed by: 7 members; Location: Punjab; Thanked: 31 times

by fiza gupta » Sun Oct 16, 2016 6:28 am

1) x = t^n, where t is a positive integer and n is odd.
let t=4,n=3 x=64;is square root 8
let t=3,n=3 x=27,not a perfect square
NOT SUFFICIENT

2) x^0.5=k, where k is a positive integer.
x=k^2
x is a perfect square root
SUFFICIENT

Fiza Gupta

Like this post

GMAT/MBA Expert

Jay@ManhattanReview: GMAT Instructor; Posts: 3008; Joined: Mon Aug 22, 2016 6:19 amFollowed by: 34 members; Location: Grand Central / New York; Thanked: 470 times

by Jay@ManhattanReview » Fri Dec 30, 2016 4:46 am

richachampion wrote:Is the positive integer x a perfect square?

(1) x = t^n, where t is a positive integer and n is odd.
(2) x^0.5=k, where k is a positive integer.

If X is a perfect square, then X^(1/2) = C; where C is a positive integer

S1: Given that X = t^n

If t itself is a perfect square, then X = t^n is a perfect square; for example, t = 1, 4, 9, and n = 1, 3, 5, etc. The answer is YES.
However, if t itself is not a perefct square, then X = t^n is not a perfect square; for example, t = 2, 3, 5, and n = 1, 3, 5, etc. The answer is No.
No unique answer. insufficient.

S2: X^0.5 = K is the requisite condition for a number X to be a perfect square. Sufficient.

OA: B

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Barcelona | Manila | Melbourne | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review