Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
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.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart 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
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Average Speed

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 54
Joined: Tue Sep 20, 2011 7:58 amFollowed by: 1 member
Thanked: 1 times
by sparkle6 » Sun Sep 25, 2011 6:41 am
A car runs 5 successive 6 km stretches at speeds of 5 km/hr, 12 km/hr, 15 km/hr, 18 km/hr and 20 km/hr. Find the Average speed of the car

a. 8 km/hr
b. 9 km/hr
c. 11 km/hr
d. 13 km/hr
e. 18 km/hr
Top
Join the discussion
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 461
Joined: Tue May 10, 2011 9:09 amFollowed by: 3 members
Location: pune
Thanked: 36 times

by amit2k9 » Sun Sep 25, 2011 7:08 am
speed = distance/ time

distance = 5*(6/5)+12*(6/12)+ 15* (6/15)+ 18 * (6/18) + 20 * (6/20) = 30km

time = 6/5 + 6/12+ 6/15+ 6/18 + 6/20= 139/30

thus avg speed = 30*30/139 = 9km/hr approx
For Understanding Sustainability,Green Businesses and Social Entrepreneurship visit -https://aamthoughts.blocked/
(Featured Best Green Site Worldwide-https://bloggers.com/green/popular/page2)
Top
Join the discussion
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 » Sun Sep 25, 2011 10:33 am
sparkle6 wrote:A car runs 5 successive 6 km stretches at speeds of 5 km/hr, 12 km/hr, 15 km/hr, 18 km/hr and 20 km/hr. Find the Average speed of the car

a. 8 km/hr
b. 9 km/hr
c. 11 km/hr
d. 13 km/hr
e. 18 km/hr
The question should ask for the APPROXIMATE average speed.

The distance can be any value.
Let distance = 180km.

The 5 rates will yield the following times:
180/5 = 36 hours.
180/12 = 15 hours.
180/15 = 12 hours.
180/18 = 10 hours.
180/20 = 9 hours.

Total distance = 5*180 = 900km.
Total time = 36+15+12+10+9 = 82 hours.
Average speed = 900/82 ≈ 11.

The correct answer is C.
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
Senior | Next Rank: 100 Posts
Posts: 54
Joined: Tue Sep 20, 2011 7:58 amFollowed by: 1 member
Thanked: 1 times

by sparkle6 » Sun Sep 25, 2011 11:48 pm
Don't we need to use 6 km somehow for the distance?
Top
Join the discussion
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 » Mon Sep 26, 2011 2:58 am
sparkle6 wrote:Don't we need to use 6 km somehow for the distance?
Nope. Since the question is asking for the AVERAGE speed, and the SAME DISTANCE is being traveled at each speed, we can plug in ANY VALUE for the distance.
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
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Wed Sep 14, 2011 12:34 am

by seema19 » Mon Sep 26, 2011 4:01 am
I didn't get the above reply. Can someone plz elaborate..
Top
Join the discussion
Junior | Next Rank: 30 Posts
Posts: 23
Joined: Wed Sep 14, 2011 12:34 am

by seema19 » Mon Sep 26, 2011 4:02 am
I didn't get the above reply. Can someone plz elaborate..
Top
Join the discussion
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 » Mon Sep 26, 2011 4:48 am
seema19 wrote:I didn't get the above reply. Can someone plz elaborate..
Let d = the distance traveled at each speed.

The 5 rates will yield the following times:
d/5, d/12, d/15, d/18, and d/20.

Total time = d/5 + d/12 + d/15 + d/18 + d/20 = 36d/180 + 15d/180 + 12d/180 + 10d/180 + 9d/180 = 82d/180.
Total distance = 5d.
Average rate = (total distance)/(total time) = 5d/(82d/180) = (5d*180)/82d = 900d/82d = 900/82 ≈ 11.

The value of d is irrelevant: notice how it cancels out in the fraction above.
Whatever the value of d, the average speed will be approximately 11kph.
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