It is currently 25 Jun 2017, 10:34

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Set T consists of 19 elements. The average of set T is L. If

Author Message
TAGS:

Hide Tags

Manager
Joined: 22 Jun 2011
Posts: 194
Location: France
Concentration: Strategy, Finance
Schools: HEC Paris - Class of 2015
GMAT 1: 700 Q47 V39
GPA: 3.35
WE: Information Technology (Mutual Funds and Brokerage)
Set T consists of 19 elements. The average of set T is L. If [#permalink]

Show Tags

24 Jul 2011, 10:29
2
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

41% (04:12) correct 59% (02:26) wrong based on 71 sessions

HideShow timer Statistics

Set T consists of 19 elements. The average of set T is L. If a new element is added to the set and the average grows by K, what is the value of the new element?

a) L(1 + K / 5)
b) L * (K/100) - 20L
c) 20L(1+K/100)
d) 20(1+K/100)-19L
e) L*(K/5)-19L

GMATClub Toolkit DS Question 93

Spoiler:
My question: So when a question mentions grows by is that always a percentage? In this case, based on the answer, it seems that K is a percentage. Shouldn't it say grows by K% if its a percentage? Or does the word grows is enough to make the % implicit?

In the answer it calculates the new average as (1 + K/100) L whereas I was trying L + K.

[Reveal] Spoiler: OA
Manager
Joined: 28 May 2011
Posts: 193
Location: United States
GMAT 1: 720 Q49 V38
GPA: 3.6
WE: Project Management (Computer Software)
Re: GMATClub Toolkit DS Question 93 [#permalink]

Show Tags

24 Jul 2011, 22:15
I'll go with you.

If questions says "Grows by K", I'd take it as grows by K in absolute terms. If questions wants to convey the "K in percentage terms" , it should say so explicitly.

this can not be taken as implicit.
_________________

-------------------------------------------------------------------------------------------------------------------------------
http://gmatclub.com/forum/a-guide-to-the-official-guide-13-for-gmat-review-134210.html
-------------------------------------------------------------------------------------------------------------------------------

VP
Joined: 24 Jul 2011
Posts: 1253
GMAT 1: 780 Q51 V48
GRE 1: 1540 Q800 V740
Re: GMATClub Toolkit DS Question 93 [#permalink]

Show Tags

25 Jul 2011, 02:38
2
KUDOS
On the GMAT, whenever something grows by a percentage, you will find it explicitly mentioned. In this instance, grows by K means growing by a factor of K, not by k%.

Remember that these three things are different:
1. Grows by k: This means literally adding k to the original number. If the original number is x, the result is x+k.
2. Grows by k times: This means the new number is the old number plus k times the number. If the original number is x, the result is x + kx = x (1+k)
3. Grows to k times: This means the new number is simply k times the old number. If the original number is x, the result is kx.
4. Grows by k%: In this case, we simply add k% of the number to itself. If the original number is x, the result is x(1 + k/100)
_________________

GyanOne | Top MBA Rankings and MBA Admissions Blog

Premium MBA Essay Review|Best MBA Interview Preparation|Exclusive GMAT coaching

Get a FREE Detailed MBA Profile Evaluation | Call us now +91 98998 31738

Manager
Status: folding sleeves up
Joined: 26 Apr 2013
Posts: 158
Location: India
Concentration: Finance, Strategy
GMAT 1: 530 Q39 V23
GMAT 2: 560 Q42 V26
GPA: 3.5
WE: Consulting (Computer Hardware)
Re: Set T consists of 19 elements. The average of set T is L. If [#permalink]

Show Tags

17 Sep 2013, 11:56
gr8tWo wrote:
Set T consists of 19 elements. The average of set T is L. If a new element is added to the set and the average grows by K, what is the value of the new element?

a) L(1 + K / 5)
b) L * (K/100) - 20L
c) 20L(1+K/100)
d) 20(1+K/100)-19L
e) L*(K/5)-19L

GMATClub Toolkit DS Question 93

Spoiler:
My question: So when a question mentions grows by is that always a percentage? In this case, based on the answer, it seems that K is a percentage. Shouldn't it say grows by K% if its a percentage? Or does the word grows is enough to make the % implicit?

In the answer it calculates the new average as (1 + K/100) L whereas I was trying L + K.

Sol: according to the literal meaning of the question

(L+k)= (19L+X)/20
X= new value

X= L+20K
Intern
Joined: 17 Mar 2013
Posts: 6
Location: United States
Concentration: General Management, Operations
GMAT Date: 10-03-2013
GPA: 3.6
WE: Information Technology (Computer Software)
Re: Set T consists of 19 elements. The average of set T is L. If [#permalink]

Show Tags

18 Sep 2013, 22:39
1
KUDOS
Here according to the problem description, "the average grows by K" --> which implies that the new average will be "L+k"

Solution :

Let's assume the value of new element to be "a". So converting the word problem into equation,

(19*L + a) / (19 + 1) = L + k ==> after solving the equation we will get a (value of newly added element) = L + 20K

But according to the answer options, problem writer wanted to convey " k% percent rise in average value " .

If we consider this case than resulting equation will be,

(19*L + a) / ( 19+1 ) = L + (K/100)*L ==> 19L + a = 20 [ L + KL/100]

==> a= 20L + KL/5 -19L

==> a= L + KL/5 , which is equivalent to option [A]
_________________

Hit +1 ! If you find my post useful

Re: Set T consists of 19 elements. The average of set T is L. If   [#permalink] 18 Sep 2013, 22:39
Similar topics Replies Last post
Similar
Topics:
28 A set of 5 numbers has an average of 50. The largest element in the 10 06 Mar 2017, 23:10
2 Set A, B, and C consist of the following elements: 3 11 Dec 2016, 00:31
7 Set A consists of integers {3, -8, Y, 19, -6} and Set B 12 11 Dec 2016, 21:42
3 Set T consist of 19 elements. The average of set T is L. If 9 18 Dec 2016, 17:37
1 A set consist of 2n-1 element. What is the number of subsets 2 29 Dec 2013, 17:31
Display posts from previous: Sort by