Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 04 Aug 2013
Posts: 101
Location: India
GPA: 3
WE: Manufacturing and Production (Pharmaceuticals and Biotech)

Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
25 Nov 2014, 21:44
Question Stats:
39% (01:09) correct 61% (01:37) wrong based on 184 sessions
HideShow timer Statistics
Set A consists of a series of unique numbers. When added together, the numbers of Set A total 140. How many of the numbers within the set are above the median? (1) The average of the set of numbers is equal to its median. (2) The average of the set of numbers is equal to 28. try to get the twist
Official Answer and Stats are available only to registered users. Register/ Login.



Senior RC Moderator
Status: It always seems impossible until it's done!!
Joined: 29 Aug 2012
Posts: 1174
Location: India
WE: General Management (Aerospace and Defense)

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
25 Nov 2014, 22:40
anceer wrote: Set A consists of a series of unique numbers. When added together, the numbers of Set A total 140. How many of the numbers within the set are above the median? 1. The average of the set of numbers is equal to its median. 2. The average of the set of numbers is equal to 28. try to get the twist Statement 1: We don't know much about the average. So not sufficient to solve. Statement 2: If Average=28. Let n be the total number in the set. We are given the sum of numbers, we know that sum divided by total number(n) will equal average. So \(\frac{140}{n}= 28\) , Now, \(\frac{140}{28}= n\) => \(n=5\). We now know the total number of numbers in the set. let x be the median. And, x2, x1, x, x+1, x+2 be the numbers. We are given \((x2) +(x1)+x +(x+1) + (x+2)= 140\).> \(5x=140\) x=28. So median is 28. Then the numbers above the median in 29 and 30. So there are 2 numbers above median. Statement 2 is sufficient. Answer is B.
_________________
Become a GMAT Club Premium member to avail lot of discounts



Math Expert
Joined: 02 Sep 2009
Posts: 46991

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
26 Nov 2014, 05:58
Gnpth wrote: anceer wrote: Set A consists of a series of unique numbers. When added together, the numbers of Set A total 140. How many of the numbers within the set are above the median? 1. The average of the set of numbers is equal to its median. 2. The average of the set of numbers is equal to 28. try to get the twist Statement 1: We don't know much about the average. So not sufficient to solve. Statement 2: If Average=28. Let n be the total number in the set. We are given the sum of numbers, we know that sum divided by total number(n) will equal average. So \(\frac{140}{n}= 28\) , Now, \(\frac{140}{28}= n\) => \(n=5\). We now know the total number of numbers in the set. let x be the median. And, x2, x1, x, x+1, x+2 be the numbers. We are given \((x2) +(x1)+x +(x+1) + (x+2)= 140\).> \(5x=140\) x=28. So median is 28. Then the numbers above the median in 29 and 30. So there are 2 numbers above median. Statement 2 is sufficient. Answer is B. Comment for (2): We have that the median of 5 distinct numbers is 28: {a, b, 28, c, d}. Thus two numbers must be greater than the median.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Intern
Status: Miles to go....before i sleep
Joined: 26 May 2013
Posts: 16
Location: India
Concentration: Finance, Marketing

Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
26 Nov 2014, 10:39
Hi Gnpth
How did you come up with the following assumption?
let x be the median. And,
x2, x1, x, x+1, x+2 be the numbers.
Since we are given in the question that Set A consists of a series of unique numbers, but we are not given that those unique numbers are consecutive numbers, if they are not consecutive numbers, the series might be different



Manhattan Prep Instructor
Joined: 22 Mar 2011
Posts: 1289

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
27 Nov 2014, 00:57
You don't need to assume that the numbers are consecutive. If you know there are 5 numbers and they're all different ("unique"), by definition two of them will be greater than the median. In addition to the consecutive set, we could have any of these: 0, 5, 28, 50, 57 1, 2, 3, 4, 130 1,000,000; 100; 0, 100; 1,000,140 You get the idea . . .
_________________
Dmitry Farber  Manhattan GMAT Instructor  New York
Manhattan GMAT Discount  Manhattan GMAT Course Reviews  View Instructor Profile  Manhattan GMAT Reviews



Intern
Joined: 07 May 2016
Posts: 27

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
03 Nov 2016, 18:51
Looked at this problem again and realized OA is wrong.
Please look at the following set:
27 27 27 27 32
Adds up to 140, has mean: 28 median:27. Only 1 number is more than the median.
Same assumption (II) we can create set 26 27 28 29 30 which has median 28 and 2 numbers more than the median.
Someone please confirm and correct the OA.



Manhattan Prep Instructor
Joined: 22 Mar 2011
Posts: 1289

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
03 Nov 2016, 19:08
Watch out for those constraints! "Set A consists of a series of unique numbers."
_________________
Dmitry Farber  Manhattan GMAT Instructor  New York
Manhattan GMAT Discount  Manhattan GMAT Course Reviews  View Instructor Profile  Manhattan GMAT Reviews



Intern
Joined: 19 Oct 2015
Posts: 1

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
04 Nov 2016, 01:49
r0ckst4r wrote: Looked at this problem again and realized OA is wrong.
Please look at the following set:
27 27 27 27 32
Adds up to 140, has mean: 28 median:27. Only 1 number is more than the median.
Same assumption (II) we can create set 26 27 28 29 30 which has median 28 and 2 numbers more than the median.
Someone please confirm and correct the OA. Stem says Set of Unique Numbers.. so not all can be same



Intern
Joined: 14 Dec 2017
Posts: 1

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
27 Dec 2017, 07:29
hey, what if the set was 1,2,3,4,130 then 1 number above right? or im missing snth?



PS Forum Moderator
Joined: 25 Feb 2013
Posts: 1180
Location: India
GPA: 3.82

Re: Set A consists of a series of unique numbers. When added together, the [#permalink]
Show Tags
27 Dec 2017, 08:50
lenaon wrote: hey, what if the set was 1,2,3,4,130 then 1 number above right? or im missing snth? Hi lenaonthe role of statement 2 is to tell that the set has 5 elements. Once you know this fact and you also know that all the elements are unique, so median will be the middle number of the set and there will be 2 elements that will be above/below the median




Re: Set A consists of a series of unique numbers. When added together, the
[#permalink]
27 Dec 2017, 08:50






