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

 It is currently 16 Feb 2020, 22:45

### 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

# When a student weighing 68 kgs joins a group of 8 students, the averag

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 61189
When a student weighing 68 kgs joins a group of 8 students, the averag  [#permalink]

### Show Tags

31 Dec 2019, 02:07
00:00

Difficulty:

35% (medium)

Question Stats:

63% (02:05) correct 38% (01:44) wrong based on 16 sessions

### HideShow timer Statistics

When a student weighing 68 kgs joins a group of 8 students, the average of the group increases by 1.5 kgs. Find the average of the original group.

A. 53
B. 54.5
C. 56
D. 57.5
E. None of these

_________________
Intern
Joined: 30 Dec 2019
Posts: 6
When a student weighing 68 kgs joins a group of 8 students, the averag  [#permalink]

### Show Tags

02 Jan 2020, 05:24
Let the initial average be A.
So, the sum of weights of all the students = 8A.

When new student joins, the sum would be 8A + 68 and average becomes A + 1.5.
Now the new average can be written as New Sum/New number of students

So, A + 1.5 = (8A + 68)/9
or, 9A + 13.5 = 8A + 68
=> A = 54.5

Option (B)
Board of Directors
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4849
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
Re: When a student weighing 68 kgs joins a group of 8 students, the averag  [#permalink]

### Show Tags

02 Jan 2020, 08:01
Bunuel wrote:
When a student weighing 68 kgs joins a group of 8 students, the average of the group increases by 1.5 kgs. Find the average of the original group.

A. 53
B. 54.5
C. 56
D. 57.5
E. None of these

$$8x + 68 = 9(x + 1.5)$$

Or, $$8x + 68 = 9x + 13.5$$

Or, $$x = 54.5$$

Hence, Answer must be (B)
_________________
Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )
Re: When a student weighing 68 kgs joins a group of 8 students, the averag   [#permalink] 02 Jan 2020, 08:01
Display posts from previous: Sort by

# When a student weighing 68 kgs joins a group of 8 students, the averag

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

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