• 5-Day Free Trial
5-day free, full-access trial TTP Quant

Available with Beat the GMAT members only code

• FREE GMAT Exam
Know how you'd score today for $0 Available with Beat the GMAT members only code • 5 Day FREE Trial Study Smarter, Not Harder Available with Beat the GMAT members only code • Free Practice Test & Review How would you score if you took the GMAT Available with Beat the GMAT members only code • Free Veritas GMAT Class Experience Lesson 1 Live Free Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

Available with Beat the GMAT members only code

• Get 300+ Practice Questions
25 Video lessons and 6 Webinars for FREE

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

Steve traveled the first 2 hours of his journey...

tagged by: BTGmoderatorLU

Top Member

Steve traveled the first 2 hours of his journey...

Steve traveled the first 2 hours of his journey at 40 mph and the remaining 3 hours of his journey at 80 mph. What is his average speed for the entire journey?

A. 60 mph
B. 56.67 mph
C. 53.33 mph
D. 64 mph
E. 66.67 mph

The OA is D.

I'm confused by this PS question. Experts, any suggestion, please? Thanks in advance.

GMAT/MBA Expert

Senior | Next Rank: 100 Posts
Joined
16 Dec 2014
Posted:
94 messages
Followed by:
4 members
Upvotes:
2
GMAT Score:
770
Top Reply
LUANDATO wrote:
Steve traveled the first 2 hours of his journey at 40 mph and the remaining 3 hours of his journey at 80 mph. What is his average speed for the entire journey?

A. 60 mph
B. 56.67 mph
C. 53.33 mph
D. 64 mph
E. 66.67 mph

The OA is D.

I'm confused by this PS question. Experts, any suggestion, please? Thanks in advance.
Speed = Distance/Time
OR
Distance = Speed * Time

Part 1: D1 = 40*2 = 80

Part 2: D2 = 80*3 = 240

Total Distance = D1 + D2 = 80 + 240 = 320
Total Time = 2 + 3 = 5

Speed = 320/5 = 64 mph

Answer is D

GMAT/MBA Expert

GMAT Instructor
Joined
25 May 2010
Posted:
14736 messages
Followed by:
1849 members
Upvotes:
13060
GMAT Score:
790
LUANDATO wrote:
Steve traveled the first 2 hours of his journey at 40 mph and the remaining 3 hours of his journey at 80 mph. What is his average speed for the entire journey?

A. 60 mph
B. 56.67 mph
C. 53.33 mph
D. 64 mph
E. 66.67 mph
2 hours are spent at 40mph.
3 hours are spent at 80mph.
Average speed for all 5 hours = (2*40 + 3*80)/5 = 320/5 = 64.

The correct answer is D.

_________________
Mitch Hunt
Private Tutor for the GMAT and GRE
GMATGuruNY@gmail.com

If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.

Available for tutoring in NYC and long-distance.
For more information, please email me at GMATGuruNY@gmail.com.
Student Review #1
Student Review #2
Student Review #3

Free GMAT Practice Test How can you improve your test score if you don't know your baseline score? Take a free online practice exam. Get started on achieving your dream score today! Sign up now.

GMAT/MBA Expert

Legendary Member
Joined
14 Jan 2015
Posted:
2667 messages
Followed by:
121 members
Upvotes:
1153
GMAT Score:
770
LUANDATO wrote:
Steve traveled the first 2 hours of his journey at 40 mph and the remaining 3 hours of his journey at 80 mph. What is his average speed for the entire journey?

A. 60 mph
B. 56.67 mph
C. 53.33 mph
D. 64 mph
E. 66.67 mph

The OA is D.

I'm confused by this PS question. Experts, any suggestion, please? Thanks in advance.
Mitch's and Dan's approach is probably simplest. But here's a fun alternative:

If Steve had spent the same amount of time traveling at each speed, his average would have been right in the middle of 40 and 80, or 60mph. We know he spent more time traveling at the faster speed, and thus, his average must be more than 60. That leaves us D and E.

Now we can test one of the two remaining choices and see if we get a 3:2 ratio in favor of time spent traveling at 80mph.
Test D: 64
Plot the rates on a number line:
40-----------------64-----------80
Gaps:-------24----------16--------
Ratio of time spent at 80 mph to 40 mph: 24:16 = 3:2. And we've got our answer.

_________________
Veritas Prep | GMAT Instructor

Veritas Prep Reviews
Save \$100 off any live Veritas Prep GMAT Course

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

Top First Responders*

1 Jay@ManhattanReview 81 first replies
2 Brent@GMATPrepNow 71 first replies
3 fskilnik 55 first replies
4 GMATGuruNY 37 first replies
5 Rich.C@EMPOWERgma... 16 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

Most Active Experts

1 fskilnik

GMAT Teacher

202 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

163 posts
3 Scott@TargetTestPrep

Target Test Prep

118 posts
4 Jay@ManhattanReview

Manhattan Review

94 posts
5 Max@Math Revolution

Math Revolution

94 posts
See More Top Beat The GMAT Experts