BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

OG The average score on a test taken by 10 students

Expert replies
by AbeNeedsAnswers » Thu Jul 27, 2017 9:20 pm
The average (arithmetic mean) score on a test taken by 10 students was x. If the average score for 5 of the students was 8, what was the average score, in terms of x, for the remaining 5 students who took the test?

A) 2x - 8
B) x - 4
C) 8 - 2x
D) 16 - x
E) 8 - (2/x)

A
Join the discussion
Source: — Problem Solving |

by Jay@ManhattanReview » Thu Jul 27, 2017 9:25 pm
AbeNeedsAnswers wrote:The average (arithmetic mean) score on a test taken by 10 students was x. If the average score for 5 of the students was 8, what was the average score, in terms of x, for the remaining 5 students who took the test?

A) 2x - 8
B) x - 4
C) 8 - 2x
D) 16 - x
E) 8 - (2/x)

A
Total score of all the 10 students = Total score of the first batch of 5 students + Total score of the second batch of 5 students

We have,

Total score of all the 10 students = 10*x = 10x;
Total score of the first batch of 5 students = 5*8 = 40;

Thus,
Total score of the second batch of 5 students = 10x - 40 = 10(x - 4);

Thus, the average score of the second batch of 5 students = 10(x - 4) / 5 = 2(x - 4) = [spoiler]2x - 8[/spoiler].

The correct answer: A

Hope this helps!

Download free ebook: Manhattan Review GMAT Quantitative Question Bank Guide

-Jay
_________________
Manhattan Review GMAT Prep

Locations: New York | Singapore | Doha | Lausanne | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
Join the discussion

by [email protected] » Fri Jul 28, 2017 10:56 am
Hi AbeNeedsAnswers,

This question can be solved by TESTing VALUES.

We're told that average score on a test taken by 10 students = X and that the average score for 5 of those students was 8. We're asked for the average score of the OTHER 5 students.

IF... X = 10, then the TOTAL points for ALL 10 students = (10)(10) = 100
Since 5 of those students averaged 8 points, that accounts for (5)(8) = 40 of those 100 points.
This leaves 100 - 40 = 60 points for the remaining 5 students, which is an average of 60/5 = 12.

So we're looking for an answer that equals 12 when X=10... There's only one answer that matches...

Final Answer: A

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Join the discussion

by Ian Stewart » Fri Jul 28, 2017 11:54 am
The two groups are equal in size (5 students each), so the overall average score will just be the ordinary average of the scores of each group, because each group is equally important. If x is the average of two things, then 2x is the sum of those two things. So if y is the average we want to find,

y + 8 = 2x
y = 2x - 8
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Join the discussion

by Matt@VeritasPrep » Sun Aug 06, 2017 11:22 pm
Sum = Average * # of Things in the Set

For the whole group, Sum = 10x. For five of the group, the sum = 5*8, so the sum for the other five = 10x - 40.

The average for those five is the sum divided by five, or (10x - 40)/5, or 2x - 8.
Join the discussion

by Jeff@TargetTestPrep » Wed Aug 09, 2017 12:39 pm
AbeNeedsAnswers wrote:The average (arithmetic mean) score on a test taken by 10 students was x. If the average score for 5 of the students was 8, what was the average score, in terms of x, for the remaining 5 students who took the test?

A) 2x - 8
B) x - 4
C) 8 - 2x
D) 16 - x
E) 8 - (2/x)

A
We are given that the average score on a test taken by 10 students was x, and need to find the average score in terms of x if the average score for 5 of those students was 8.

Thus, the overall sum was 10x and the sum for the 5 students was (5)(8)= 40.

We need to determine the average of the 5 remaining students.

The sum for the 5 remaining students was 10x - 40, and thus the average is:

(10x - 40)/5 = 10x/5 - 40/5 = 2x - 8

Answer: A

Jeffrey Miller
Head of GMAT Instruction
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews
Join the discussion