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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

Exam / Average / Median

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 266
Joined: Mon Oct 19, 2009 9:46 pm
Thanked: 8 times
GMAT Score:690
by pkw209 » Tue Apr 20, 2010 3:20 pm
What is the best way to solve this one?

The scores on a certain exam were 60, 75, 100 70 and x. If the median score was 5 points lower than the average score on the exam, which of the following could be x?

a) 75

b) 80

c) 85

d) 90

e) 95

answer is e

Based on the answer choices, I was able to identify that the median had to be 75. With that info I was able to create an equation. However, if the answer choices DID NOT allow you to determine what the median was, how would you solve this problem?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 613
Joined: Thu Mar 22, 2007 6:17 amFollowed by: 64 members
Location: madrid
Thanked: 171 times
GMAT Score:790

by kevincanspain » Tue Apr 20, 2010 3:39 pm
pkw209 wrote:What is the best way to solve this one?

The scores on a certain exam were 60, 75, 100 70 and x. If the median score was 5 points lower than the average score on the exam, which of the following could be x?


60 70 75 100 x
First, the average is (305 +x)/5 = 61 + x/5

Thus the median m= 56 + x/5

Since 70 <= m <= 75

70 <= 56 +x/5 <= 75
70 <= x <= 95

Note that if 70 < m < 75, m= x
and thus 4/5 x = 56, which implies that x = 70

Thus x could be either 70 or 95

It was very wise of you to look at the answer choices, as they get you to the answer faster!
Kevin Armstrong
GMAT Instructor
Gmatclasses
Madrid
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 266
Joined: Mon Oct 19, 2009 9:46 pm
Thanked: 8 times
GMAT Score:690

by pkw209 » Tue Apr 20, 2010 4:03 pm
Thanks, Kevin. How did you know this?
Since 70 <= m <= 75
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Tue Apr 13, 2010 10:15 pm
Location: Singapore

by vvijay146 » Tue Apr 20, 2010 10:26 pm
Because Median is the middle number after arranging the numbers in Sequence. As there are 5 numbers provided, middle number is either 75 or a number between 70 & 75.

Hope that clarifies
Vijay
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pmFollowed by: 2 members
Location: Arabian Sea
Thanked: 125 times

by ajith » Wed Apr 21, 2010 1:20 am
pkw209 wrote:What is the best way to solve this one?

The scores on a certain exam were 60, 75, 100 70 and x. If the median score was 5 points lower than the average score on the exam, which of the following could be x?

a) 75

b) 80

c) 85

d) 90

e) 95

answer is e

Based on the answer choices, I was able to identify that the median had to be 75. With that info I was able to create an equation. However, if the answer choices DID NOT allow you to determine what the median was, how would you solve this problem?

average score = 61 +x/5


Case 1: If x<70
Median is 70

=> 61 + x/5 = 70 +5
x=70

Case 2: If 70<x<75
Median is x

61 +x/5 = x+5

x= 5/4*56 = 70

Case 3:
If x>75

Median is 75
61 + x/5 = 75+5

x = 19*5 = 95

So for the given conditions to prevail x has to be either 70 or 95; 95 features the options
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 610
Joined: Fri Jan 15, 2010 12:33 amFollowed by: 2 members
Thanked: 47 times

by kstv » Wed Apr 21, 2010 3:51 am
Ascending order
60 70 75 100 position of x undecided.
total of 60+70+75+100 = 305
avg. of 5 nos = (305+x)/5 = 61+ x/5
the diff from the median is 5
x cannot have 0 in its unit digit
so a, c or e
if the median is 60 70 75 or 100
then x/5 should have 9 in its unit digit.
a) 75/5 = 15 c)85/5 = 17
e) 95/5 = 19
if x is the median ?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 1462
Joined: Thu Apr 09, 2015 9:34 amFollowed by: 22 members
Location: New York, NY
Thanked: 39 times

by Jeff@TargetTestPrep » Mon Jan 08, 2018 4:53 pm
pkw209 wrote:What is the best way to solve this one?

The scores on a certain exam were 60, 75, 100 70 and x. If the median score was 5 points lower than the average score on the exam, which of the following could be x?

a) 75

b) 80

c) 85

d) 90

e) 95
The average is:

(60 + 75 + 100 + 70 + x)/5 = (305 + x)/5

Let's plug in answer choices to see which could be x, given that the median is 5 less than the average:

A) average = 380/5 = 76, and scores are 60, 70, 75, 75, 100; mean is 76 and median is 75 doesn't work.

B) average = 385/5 = 77, and scores are 60, 70, 75, 77, 100; mean is 77 and median is 75 doesn't work.

C) average = 390/5 = 78, and scores are 60, 70, 75, 85, 100; mean is 78 and median is 75 doesn't work.

D) average = 395/5 = 79, and scores are 60, 70, 75, 90, 100; mean is 79 and median is 75 doesn't work.

E) average = 400/5 = 80, and scores are 60, 70, 75, 95, 100; mean is 80 and median is 75, which is exactly 5 points less; this is possible.

Answer: E

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
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1