• 7 CATs FREE!
If you earn 100 Forum Points

Engage in the Beat The GMAT forums to earn
100 points for $49 worth of Veritas practice GMATs FREE VERITAS PRACTICE GMAT EXAMS Earn 10 Points Per Post Earn 10 Points Per Thanks Earn 10 Points Per Upvote Z is the set of the first n positive odd numbers, where .... tagged by: Vincen This topic has 1 expert reply and 0 member replies Z is the set of the first n positive odd numbers, where .... Z is the set of the first n positive odd numbers, where n is a positive integer. Given that n > k, where k is also a positive integer, x is the maximum value of the sum of k distinct members of Z, and y is the minimum value of the sum of k distinct members of Z, what is x + y? (A) kn (B) kn + k^2 (C) kn + 2k^2 (D) 2kn - k^2 (E) 2kn The OA is the option E. How can I solve this PS question? I'm really confused here. Experts, can you give me some help? GMAT/MBA Expert GMAT Instructor Joined 04 Oct 2017 Posted: 551 messages Followed by: 11 members Upvotes: 180 Top Reply Quote: Z is the set of the first n positive odd numbers, where n is a positive integer. Given that n > k, where k is also a positive integer, x is the maximum value of the sum of k distinct members of Z, and y is the minimum value of the sum of k distinct members of Z, what is x + y? (A) kn (B) kn + k^2 (C) kn + 2k^2 (D) 2kn - k^2 (E) 2kn The OA is the option E. How can I solve this PS question? I'm really confused here. Experts, can you give me some help? Hi Vincen, Let's take a look at your question. We will solve this question by assuming some random values for the set Z. Let n = 5, therefore, the set Z has first 5 positive odd numbers. i.e. $$Z=\left\{1,\ 3,\ 5,\ 7,\ 9\right\}$$ Let k = 2, then x is the is the maximum value of the sum of k=2 distinct members of Z. We can see that the two values of set Z, that will give the maximum sum are the last two values, i.e. 7 and 9. Therefore, $$x=7+9=16$$ y is the is the minimum value of the sum of k=2 distinct members of Z. We can see that the two values of set Z, that will give the minimum sum are the first two values, i.e. 1 and 3. Therefore, $$y=1+3=4$$ Now, we can find x+y: $$x+y=16+4=20$$ We had: n = 5 and k = 2 So 20 will be equal to: $$2\times5\times2=2nk$$ Therefore, option E is correct. Hope it helps. I am available if you'd like any follow up. _________________ GMAT Prep From The Economist We offer 70+ point score improvement money back guarantee. Our average student improves 98 points. Free 7-Day Test Prep with Economist GMAT Tutor - Receive free access to the top-rated GMAT prep course including a 1-on-1 strategy session, 2 full-length tests, and 5 ask-a-tutor messages. Get started now. • FREE GMAT Exam Know how you'd score today for$0

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Get 300+ Practice Questions

Available with Beat the GMAT members only code

• Award-winning private GMAT tutoring
Register now and save up to \$200

Available with Beat the GMAT members only code

Top First Responders*

1 Brent@GMATPrepNow 69 first replies
2 fskilnik@GMATH 54 first replies
3 Jay@ManhattanReview 48 first replies
4 GMATGuruNY 35 first replies
5 Rich.C@EMPOWERgma... 31 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 fskilnik@GMATH

GMATH Teacher

128 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

101 posts
3 Max@Math Revolution

Math Revolution

92 posts
4 Jay@ManhattanReview

Manhattan Review

86 posts
5 Rich.C@EMPOWERgma...

EMPOWERgmat

78 posts
See More Top Beat The GMAT Experts