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 →

sequence

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 53
Joined: Wed May 28, 2014 9:36 pmFollowed by: 1 member
by datonman » Fri Nov 14, 2014 10:10 am
In the sequence, r, s, t, if each term after the first is x more than the previous term, what is the average of r, s, and t in terms of r and x?

A) r + x

B) r + x/3

C) r + 2x/3

D) r+x/3

E) 3(r+x)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Fri Nov 14, 2014 10:26 am
datonman wrote:In the sequence, r, s, t, if each term after the first is x more than the previous term, what is the average of r, s, and t in terms of r and x?

A) r + x

B) r + x/3

C) r + 2x/3

D) r+x/3

E) 3(r+x)
Let r=2 and x=3.
Since each term is x=3 more than the previous term, we get:
r, s, t = 2, 5, 8.
Average of r, s and t = (2+5+8)/3 = 5. This is our target.

Now plug r=2 and x=3 into the answers to see which yields our target of 5.
Only A works:
r+x = 2+3 = 5.

The correct answer is A.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pmFollowed by: 1268 members
Location: Vancouver, BC
Thanked: 5254 times
GMAT Score:770

by Brent@GMATPrepNow » Fri Nov 14, 2014 10:30 am
datonman wrote:In the sequence, r, s, t, if each term after the first is x more than the previous term, what is the average of r, s, and t in terms of r and x?

A) r + x

B) r + x/3

C) r + 2x/3

D) r+x/3

E) 3(r+x)
Another approach:

There's a nice rule that says, "In a set where the numbers are equally spaced, the mean will equal the median."

Since each term is x greater than the term before it, these values are equally spaced.

So, the mean (average) = the median
Here, the median is s, so the average must be s
HOWEVER, the question wants the answer in terms of r and x.
We know that s is x greater than r
So, s = r + x
So, the mean = median = s = r + x

Answer: A

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 447
Joined: Fri Nov 08, 2013 7:25 amFollowed by: 1 member
Thanked: 25 times

by Mathsbuddy » Wed Nov 19, 2014 7:32 am
The 3 terms are: r, r+x, r + 2x
The total is 3r + 3x
So the mean average is (3r + 3x)/3 = r + x
Answer = A
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1