GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 20 Aug 2018, 03:50

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

The average (arithmetic mean) of the five numbers x, 91, 120, 134, and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
B
Joined: 26 Apr 2018
Posts: 3
The average (arithmetic mean) of the five numbers x, 91, 120, 134, and  [#permalink]

Show Tags

New post Updated on: 30 Jul 2018, 02:40
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

62% (01:21) correct 38% (01:02) wrong based on 29 sessions

HideShow timer Statistics

The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?

(A) 20%
(B) 22%
(C) 25%
(D) 30%
(E) It cannot be determined from the information given.

Originally posted by bettatantalo on 30 Jul 2018, 02:24.
Last edited by Bunuel on 30 Jul 2018, 02:40, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48044
Re: The average (arithmetic mean) of the five numbers x, 91, 120, 134, and  [#permalink]

Show Tags

New post 30 Jul 2018, 02:43
1
1
bettatantalo wrote:
The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?

(A) 20%
(B) 22%
(C) 25%
(D) 30%
(E) It cannot be determined from the information given.


The average of five numbers = (sum of the numbers)/5. So, the average of five numbers is 1/5, or 20% of the sum.

Answer: A.
_________________

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?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
User avatar
B
Status: No Progress without Struggle
Joined: 04 Aug 2017
Posts: 28
Location: Armenia
GPA: 3.4
The average (arithmetic mean) of the five numbers x, 91, 120, 134, and  [#permalink]

Show Tags

New post 30 Jul 2018, 22:45
bettatantalo wrote:
The average (arithmetic mean) of the five numbers x, 91, 120, 134, and 220 is what percent of the sum of the five numbers?

(A) 20%
(B) 22%
(C) 25%
(D) 30%
(E) It cannot be determined from the information given.


You can either think logically and immediately choose the choice A or do algebraically and see the same result. In both cases, the logic plays a monumental role in this problem.

Finding Average: \(\frac{x+565}{5}\)

[b]The Sum
x+565

The Sum is the total and the average is the part, so you can create an equation: \(\frac{x+565}{5}\) / x+565 = \(\frac{y%}{100%}\)
You can see that we have two variables x and y, but have only one equation. So, algebraically it's somehow impossible to find x and y. But you also can notice that you divide the numerator of the first fraction into 5, which in percent form is 100/5 yields 20%.
_________________

Seryozha Sargsyan 21

Contact: sargsyanseryozha@gmail.com

What you think, you become,
What you feel, you attract,
What you imagine, you create.

e-GMAT Representative
User avatar
P
Joined: 04 Jan 2015
Posts: 1900
The average (arithmetic mean) of the five numbers x, 91, 120, 134, and  [#permalink]

Show Tags

New post 30 Jul 2018, 23:55
1

Solution



Given:
    • We are given 5 numbers: x, 91, 120, 134, and 220

To find:
    • Arithmetic mean of : x, 91, 120, 134, and 220 is what percent of the sum of the five numbers

Approach and Working:

\(Average= \frac{Sum\ of\ the\ five\ numbers}{5}\)

Method:1

Hence, Average if \(\frac{1}{5}\) of sum of the five numbers.
Thus, average is 20% of sum of the five number.

Method:2

• To convert average to percentage, we can multiply by 100.
• Average= Sum of the five numbers/5 *100%= Average= 20% of Sum of the five numbers


Hence, the correct answer is option A.

Answer: A
_________________








Register for free sessions
Number Properties | Algebra |Quant Workshop

Success Stories
Guillermo's Success Story | Carrie's Success Story

Ace GMAT quant
Articles and Question to reach Q51 | Question of the week

Must Read Articles
Number Properties – Even Odd | LCM GCD
Word Problems – Percentage 1 | Percentage 2 | Time and Work 1 | Time and Work 2 | Time, Speed and Distance 1 | Time, Speed and Distance 2
Advanced Topics- Permutation and Combination 1 | Permutation and Combination 2 | Permutation and Combination 3 | Probability
Geometry- Triangles 1 | Triangles 2 | Triangles 3 | Common Mistakes in Geometry
Algebra- Wavy line

Practice Questions
Number Properties 1 | Number Properties 2 | Algebra 1 | Geometry | Prime Numbers | Absolute value equations | Sets



| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com

The average (arithmetic mean) of the five numbers x, 91, 120, 134, and &nbs [#permalink] 30 Jul 2018, 23:55
Display posts from previous: Sort by

The average (arithmetic mean) of the five numbers x, 91, 120, 134, and

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.