GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 22 Feb 2020, 18:28

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

In a class of 5 students, average weight of the 4 lightest students is

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

Hide Tags

Find Similar Topics 
Manager
Manager
avatar
G
Joined: 09 Apr 2017
Posts: 50
Location: Nepal
Concentration: Finance, Entrepreneurship
Schools: Johnson '22 (S)
GMAT 1: 580 Q47 V22
GMAT 2: 640 Q48 V29
GMAT 3: 690 Q48 V36
WE: Information Technology (Computer Software)
Reviews Badge
In a class of 5 students, average weight of the 4 lightest students is  [#permalink]

Show Tags

New post 04 Sep 2018, 01:22
1
4
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

41% (02:13) correct 59% (03:08) wrong based on 34 sessions

HideShow timer Statistics

In a class of 5 students, average weight of the 4 lightest students is 40 kgs, Average weight of the 4 heaviest students is 45 kgs. What is the difference between the the maximum and minimum possible average weight overall?

a. 2.8 kgs
b. 3.2 kgs
c. 3 kgs
d. 4 kgs
e. 4.2 kgs
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 8249
Re: In a class of 5 students, average weight of the 4 lightest students is  [#permalink]

Show Tags

New post 04 Sep 2018, 01:57
1
pratik2018 wrote:
In a class of 5 students, average weight of the 4 lightest students is 40 kgs, Average weight of the 4 heaviest students is 45 kgs. What is the difference between the the maximum and minimum possible average weight overall?

a. 2.8 kgs
b. 3.2 kgs
c. 3 kgs
d. 4 kgs
e. 4.2 kgs



Maximum..
Let the weight of the lighted 4 be same so the weight of each is 40.
Now the heaviest 4 weigh 45*4=180
All 5 will weigh 180+40=220
Average = 220/5=44

Minimum
Let the heaviest 4 be same so 45 each
Total weight of 5 will be 40*4+45=205
Average = 205/5=41

Difference=44-41=3

C
_________________
Target Test Prep Representative
User avatar
V
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 9443
Location: United States (CA)
Re: In a class of 5 students, average weight of the 4 lightest students is  [#permalink]

Show Tags

New post 07 Sep 2018, 16:01
pratik2018 wrote:
In a class of 5 students, average weight of the 4 lightest students is 40 kgs, Average weight of the 4 heaviest students is 45 kgs. What is the difference between the the maximum and minimum possible average weight overall?

a. 2.8 kgs
b. 3.2 kgs
c. 3 kgs
d. 4 kgs
e. 4.2 kgs



Let a, b, c, d and e be the weights of the 5 students such that a ≤ b ≤ c ≤ d ≤ e. Since the total weight of the 4 lightest students is 4 x 40 = 160 kg, we have a + b + c + d = 160. Similarly, since the total weight of the 4 heaviest students is 4 x 45 = 180 kg, we have b + c + d + e = 180. We need to determine the maximum and minimum value of (a + b + c + d + e)/5.

The maximum average weight of all 5 students occurs when a is as large as possible. However, since the average weight of the 4 lightest students is 40 kg, a is at most 40, so the maximum average weight is:

(a + b + c + d + e)/5 = (a + 180)/5 = a/5 + 180/5 = 40/5 + 36 = 8 + 36 = 44 kg

The minimum average weight of all 5 students occurs when e is as small as possible. However, since the average weight of the 4 heaviest students is 45 kg, e is at least 45 kg, so the minimum average weight is:

(a + b + c + d + e)/5 = (160 + e)/5 = 160/5 + e/5 = 32 + 45/5 = 32 + 9 = 41 kg

Therefore, the difference between the maximum and minimum average weight is 44 - 41 = 3 kg.

Answer: C
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
181 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 14124
Re: In a class of 5 students, average weight of the 4 lightest students is  [#permalink]

Show Tags

New post 02 Jan 2020, 08:25
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Club Bot
Re: In a class of 5 students, average weight of the 4 lightest students is   [#permalink] 02 Jan 2020, 08:25
Display posts from previous: Sort by

In a class of 5 students, average weight of the 4 lightest students is

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





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