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

Redeem

Im still confused abt this question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 19
Joined: Mon Mar 21, 2011 2:57 pm

Im still confused abt this question

by tvtt2010 » Thu Aug 18, 2011 4:23 pm
if n and k are integers whose product is 400, which of the following statements must be true?
A. n+k>0
B. n#k
C. either n or k is multiple of 10
D. if n is even, then k is odd
E. if n is odd, then k is even

what is the different between D and E? They both indicate the same thing that: one of each is odd or even

Thanks
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 965
Joined: Thu Jan 28, 2010 12:52 am
Thanked: 156 times
Followed by:34 members
GMAT Score:720

by vineeshp » Thu Aug 18, 2011 7:02 pm
You cant say that. D and E are specifically different numbers here. So n is n and k is k. You cannot interchange. Hence if n is odd, then they dont meant one of the numbers is odd, they mean n specifically is odd.
Vineesh,
Just telling you what I know and think. I am not the expert. :)
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Thu Aug 18, 2011 7:09 pm
tvtt2010 wrote:what is the different between D and E? They both indicate the same thing that: one of each is odd or even
In fact they are completely opposite as n and k are different integers.
If n and k are integers whose product is 400, which of the following statements must be true?
A. n+k>0
B. n#k
C. either n or k is multiple of 10
D. if n is even, then k is odd
E. if n is odd, then k is even
A. n = k = -20 --> (n +k) = -40 < 0 ----> FALSE
2. n = k = 20 ---------------------------> FALSE
3. n = 16 and k = 25 --------------------> FALSE
4. n = 2 and k = 400 --------------------> FALSE
5. If n is odd then k must be even as their product is even ---> TRUE

The correct answer is E.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 164
Joined: Sun Jul 18, 2010 5:26 am
Thanked: 49 times
Followed by:4 members
GMAT Score:710

by Maciek » Fri Aug 19, 2011 6:15 am
Hi :)

I like the way the problem was explained by the expert.

Moreover, it is worth to remember about the roles of antecedent and consequent of a conditional.
The antecedent of a conditional is a sufficient condition for the consequent.
The consequent of a conditional is a necessary condition for the antecedent.
Thus:

D)
Antecedent: n is even
Consequent: k is odd

E)
Antecedent: n is odd
Consequent: k is even

You cannot interchange the sentences D) and E).

If you want to read more about necessary and sufficient conditions, you may check Critical Reasoning: A User's Manual: www.ou.edu/ouphil/faculty/chris/crmscreen.pdf

Hope it helps!

Best,
Maciek
"There is no greater wealth in a nation than that of being made up of learned citizens." Pope John Paul II

if you have any questions, send me a private message!

should you find this post useful, please click on "thanks" button :)
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8086
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Mon Feb 04, 2019 5:28 pm
tvtt2010 wrote:if n and k are integers whose product is 400, which of the following statements must be true?
A. n+k>0
B. n#k
C. either n or k is multiple of 10
D. if n is even, then k is odd
E. if n is odd, then k is even
Let's go through the choices.

Since n can be -20 and k can be -20, we see that choice A is not true.

Since n can be 20 and k can be 20, we see that choice B is not true.

Since 400 = 16 x 25, we see that choice C is not true.

Since 400 = 20 x 20, we see that choice D is not true.

So choice E must be true. We can also show that it must be true because if n is odd, then k must be even, in order to produce an even product (400 is an even number). For example, if n is 25 (odd), then k must be even, which it is, since k must be 16.

Answer: E

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Post new topic Post Reply
• Page 1 of 1