Integer problem

Expert replies

Vishnu88: Senior | Next Rank: 100 Posts; Posts: 35; Joined: Thu Feb 03, 2011 11:07 amFollowed by: 1 member; Location: Chennai, India; Thanked: 1 times

by Vishnu88 » Sat May 07, 2011 2:34 am

If x and y are nonzero integers, is x/y an integer?

1. x is a product of 2 and some other integer
2. There is only one pair of positive integers whose product equals y

Appreciate if you could elaborate on statement 2 and explain how it is used in deriving the right answer.

Cheers!

Like this post

Source: Beat The GMAT — Data Sufficiency | Sat May 07, 2011 2:34 am

pemdas: Legendary Member; Posts: 1084; Joined: Fri Apr 15, 2011 2:33 pmFollowed by: 21 members; Thanked: 158 times

by pemdas » Sat May 07, 2011 3:32 am

confused term 'product' initially

x is not 0 means NOT all numbers can be factors of x
y is not 0 means any number is theoretically divisible by y (with the remainder or not)

this DS can be rephrased -> is y a factor of x?
st(1) x=2*i, where i is integer. (2*i)/y Not Sufficient, as we don't know y
st(2) y=f*g, where f and g are integers. Among all integers only 1 and 1 can form the unique pair (1 and 0 can't, as 0 is not +ve), hence y=1 (we are not told that one pair of different +ve integers). So x/y=x/1 Sufficient, as we know if x is any number it's divisible by 1.
IOM b

Vishnu88 wrote:If x and y are nonzero integers, is x/y an integer?

1. x is a product of 2 and some other integer
2. There is only one pair of positive integers whose product equals y

Appreciate if you could elaborate on statement 2 and explain how it is used in deriving the right answer.

Cheers!

Success doesn't come overnight!

Like this post

clock60: Legendary Member; Posts: 759; Joined: Mon Apr 26, 2010 10:15 amFollowed by: 3 members; Thanked: 85 times

by clock60 » Sat May 07, 2011 5:27 am

hi guys, my try
(1) says nothing except x is even integer
(2) i hope that it says that y is prime
any prime integer can be performed with product of 1 and itself
if y=1*2=2 it can be product of only one pair=1*2
if y is not prime say y=6,then it can be performed as
y=2*3-one pair, or 6*1-another pair.but it is not allowed according st2
so from 2 we know that y is prime but no info about x so insuff
both
x=2, y=2 here x is multiple of y, but
x=2, y=5 here x is not multiple
to me the answer is E

Like this post

champmag: Master | Next Rank: 500 Posts; Posts: 234; Joined: Tue Feb 22, 2011 5:02 amFollowed by: 3 members; Thanked: 5 times

by champmag » Sat May 07, 2011 6:10 am

IMO :E

1.) First Statement gives info only about X and that X is an even Number. So this statement is not sufficient to find whether X/Y is an integer.

2.) This statement says that Y is a prime Number----not sufficient.

Taking 1 and 2 together-

If X=2*3 Y=3, then X/Y is an integer.
If X=2*3, Y=7, the X/Y is not an integer.

So both the statements taken together are also not sufficient.

so E.

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