pls check this and help out.

Expert replies

nolf: Junior | Next Rank: 30 Posts; Posts: 22; Joined: Tue Dec 23, 2008 8:21 am; Location: INDIA; Thanked: 1 times; GMAT Score:680

by nolf » Tue Mar 17, 2009 7:18 am

Hi

i faced a problem in DS and here it is..

if x(2) + 5y = 49.. is y an integer (read as x square)...

a) 1<x<4

b) x(2) is an integer....

Now 1st option says that x lies between 1 and 4..so 2 and 3 are the options right?? so shouldnt it be enough... The answer given is (E)..

pls tell me abt this...

THanks

Harsha

Harsha

Like this post

Source: Beat The GMAT — Data Sufficiency | Tue Mar 17, 2009 7:18 am

cramya: Legendary Member; Posts: 2467; Joined: Thu Aug 28, 2008 6:14 pmFollowed by: 11 members; Thanked: 331 times

by cramya » Tue Mar 17, 2009 8:41 am

x does not have to be an integer

x = sqrt(2) y = 47/5

x=3 y=8

hence E

Like this post

Stuart@KaplanGMAT: GMAT Instructor; Posts: 3225; Joined: Tue Jan 08, 2008 2:40 pmFollowed by: 614 members; Location: Toronto; Thanked: 1710 times; GMAT Score:800

Re: pls check this and help out.

by Stuart@KaplanGMAT » Tue Mar 17, 2009 1:57 pm

nolf wrote:Hi

i faced a problem in DS and here it is..

if x(2) + 5y = 49.. is y an integer (read as x square)...

a) 1<x<4

b) x(2) is an integer....

Now 1st option says that x lies between 1 and 4..so 2 and 3 are the options right??

THanks

Harsha

We have to be very careful about the assumptions that we make.

Nowhere does it say that x must be an integer. So, x could be 1.1, 1.2, 1.3, .... - there are lots of numbers between 1 and 4 other than 2 and 3.

So, for both (1) and (2) to be true, we could have:

x = root2
x = root3
x = root4 = 2
x = root5
x = root6
x = root7

all the way up to

x = root15

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course

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